Underwater City Name Generator
Names for sunken kingdoms, merfolk cities, and deep-sea colonies
Generate underwater city names in three main styles: mythic Greek-flavored sunken kingdoms like Atlantis and Thalassaria, flowing merfolk and sea-elf settlements, and hard sci-fi deep-sea habitats like Rapture or Trench Station Kepler. Ideal for fantasy maps, D&D aquatic campaigns, and ocean sci-fi.
About underwater city names
Underwater city names fall into three families. The mythic family descends from Plato's Atlantis and Greek sea deities: Poseidon, Triton, Nereus, Thetis, Amphitrite, Oceanus, and Pontus, usually with a Greek city ending like -polis, -ia, or -os. Real drowned cities and legends belong here too, from Breton Ys and Welsh Cantre'r Gwaelod to Baltic Vineta, Russian Kitezh, Indian Dwarka, and Japanese Ryūgū. The fantasy family covers merfolk, sea elves, tritons, and sahuagin, and favors English compounds built from sea materials: Coralspire, Pearlhold, Kelpmoor, Brinewatch, or the Grotto of Silent Bells. The sci-fi family names deep-sea colonies the way we name space stations, after real habitats (Aquarius, Tektite, Conshelf), trenches (Mariana, Kermadec, Sunda), hydrothermal vents (Lost City, Rainbow, Menez Gwen), or explorers (Cousteau, Beebe).
The most memorable underwater cities also convey depth. Words like sunlit, twilight, midnight, hadal, and benthic map onto real ocean zones and tell the reader whether the city sits in a bright lagoon or a lightless trench. Rapture from BioShock works because it sounds like nothing else, and Ys because it sounds ancient.
The list also holds drowned-village names like Marlow-under-Wave, sea words from other languages like Cathair na Mara, brass-and-rivet Verne-era works, and colonies under the ice of Europa and Enceladus. Use it to name a merfolk capital, a lost civilization, or a research colony.
How to choose underwater city names
- Pick your family first (mythic Greek, fantasy compound, or sci-fi station) and stay in it; a merfolk city called Trench Station Kepler breaks the tone.
- Signal depth with the name: sunlit or reef words for shallow cities, twilight and lantern words for the mesopelagic, hadal or trench words for the deepest.
- For sci-fi habitats, follow real naming practice and combine a location with a program name or explorer, such as Habitat Aquarius or Vent Station Prometheus.
- Real legends of drowned cities (Ys, Kitezh, Vineta, Dwarka) are public domain and give a fantasy city instant history when borrowed or adapted.
- Say the name underwater-style: names with long vowels and soft consonants (Thalassia, Nereopolis, Merrowmere) sound like they belong to sea people; hard clusters sound like surface-dwellers named the place.
Frequently asked questions
Where do most underwater city names come from?
Mostly from Greek sea mythology (Poseidon, Triton, Nereus, Thalassa) and from real legends of drowned cities such as Ys in Brittany, Kitezh in Russia, Vineta on the Baltic, and Dwarka in India. Modern fantasy adds English compounds like Coralspire, and sci-fi borrows space-station naming for deep-sea habitats.
Are Atlantis and Rapture free to use in my own work?
Atlantis comes from Plato and is public domain, so you can use it freely. Rapture is BioShock's city and is included for reference only; use it as inspiration for tone rather than as your city's actual name in a commercial project.
How should I name a merfolk or triton city for D&D?
Merfolk and sea elves in most settings use flowing, vowel-heavy names (Merrowmere, Thalassaria), while tritons and older civilizations lean Greek (Tritonopolis, Ketos Deep) and sahuagin or kuo-toa places sound harsher (Sahuagin Warrens, Kuo-toa Deep). Naming by species is a quick way to make the ocean feel populated by different cultures.
What makes a good sci-fi deep-sea colony name?
Copy how real underwater habitats and space stations are named: a type word (Habitat, Station, Base, Colony) plus a program name, explorer, or geographic feature. Habitat Aquarius and Tektite were real NASA-era habitats, and trench or vent names like Mariana Reach and Lost City Vent Colony sound instantly plausible.
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All 1,000 underwater city names
A: 71 names
- Abalone Vault
- Abbots Anchor
- Aberdovey Bells
- Aboleth Deep
- Abyssal Station Alvin
- Abyssal Station Barton
- Abyssal Station Beebe
- Abyssal Station Cousteau
- Abyssal Station Mir
- Abyssalia
- Abysshaven
- Abyssopolis
- Abyssos
- Abzu
- Adlivun
- Admiral's Aquarium
- Aegae of the Sea Horses
- Aegir's Hall
- Aegirholm
- Aelunore
- Aemyrral
- Aequoria
- Agora of Okeanos
- Ahtola
- Aigaion
- Aiolos Trench
- Aktaia
- Aleutian Deep
- Alexandria Antirhodos
- Alpheios Crossing
- Altum
- Aluminaut Yard
- Alunessa
- Ambergris Vault
- Amphinome
A, continued
- Amphitheatre of the Singing Whales
- Amphithoe
- Amphitrion
- Amphitrite
- Amphitrite Colony
- Amphitritopolis
- Amphora Row
- Anchorage Below
- Andros Blue Reach
- Anemone Court
- Anemonehold
- Anglerlight
- Anthuriel Shoals
- Ao Guang's Court
- Apollonia Below
- Aqualab Nine
- Aquapolis
- Aquaria
- Aquashell Grotto
- Aquilon Habitat
- Archimède Works
- Archive of the Tide Tables
- Arcology Mariana
- Arethusa's Spring
- Argonaut Base
- Argyrothalassa
- Aronnax Gallery
- Atacama Trench Works
- Atlantis
- Atlantis Massif Base
- Atlit-Yam
- Atoll Ring City
- Auremar
- Avenue of Drifting Lamps
- Axial Seamount Colony
- Azure Atoll
B: 58 names
- Baghdad Sulcus Port
- Bahr al-Zulumat
- Baiae Below
- Bajamar
- Baleen Gate
- Ballast Street
- Ballast Tank Commons
- Ballasthold
- Baltic Anomaly Hold
- Barbscale Burrows
- Barents Deep Station
- Barnaclehold
- Barrow of the Drowned
- Bastion of Coldwater
- Bathyal Station Nemo
- Bathyhold
- Bathypelagia
- Bathyscaphe Base Trieste
- Bathysia
- Bathysphere Base
- Bathysphere Boulevard
- Beebe Vent Colony
- Bellbury-under-Brine
- Bellows Yard
- Benthesikyme
- Benthic Lab Seven
- Benthos
- Benthspire
- Beringia Below
B, continued
- Bhogavati
- Bimini Road City
- Bioluminous Reach
- Bioshell City
- Bishops Trawl
- Black Smoker Colony
- Blackgill Pits
- Bladderwrack Fen
- Blake Plateau Farm
- Bloodtide Sink
- Bluewater Flats
- Bowie Seamount Rig
- Bowsprit Bridge
- Brass Lung Works
- Brassbell
- Breaker's Edge
- Briareos Pillars
- Bridge of the Manta Kings
- Bridge Over the Black Trench
- Brightwater Bight
- Brinegarth
- Brinehold
- Brinewatch
- Brittlestar Fen
- Brizo's Harbor
- Broken Spur Vent Farm
- Bullkelp Canopy
- Bythopolis
- Bythos
C: 76 names
- Cael Ondar
- Caer Arianrhod
- Caer y Dyfnder
- Calumeth
- Calypsia
- Calypso Base
- Canopus Below
- Cantre'r Gwaelod
- Capel Celyn
- Capstan Cross
- Captain's Folly
- Carson Shelf Sanctuary
- Cascadia Reach
- Cascadia Station
- Cathair na Mara
- Cavern of the Deep Choir
- Cayman Trough Ring
- Cenote Sagrado Deep
- Ceres Brine Pocket
- Cerulean Hollow
- Ceto's Hollow
- Chalchiuhtlicue's Mirror
- Challenger Deep Station
- Chapel of the Sunken Bell
- Charybdis Rim
- Chatham Rise Aquafarm
- Chemocline Colony
- Chemosynth Reach
- Chernomor Platform
- Chertovo Below
- Chipping Shoal
- Choir of the Humpbacks
- Chrysokyma
- Chukchi Deep Colony
- Churchbell Bottom
- Citadel of Nine Currents
- Cité des Abysses
- City at the Thermocline
C, continued
- City Beneath the Storm
- City of the Second Sky
- Civitas Maris
- Clamshell Commons
- Clarion-Clipperton Nodule Yard
- Clockwork Shoals
- Cloister of Salt Monks
- Cloister of the Quiet Current
- Cockle Magna
- Codbank
- Coldseep Hollow
- Colonnade of Triton
- Conamara Chaos Shaft
- Conch Hall
- Conch Key
- Conchhaven
- Congo Canyon Reach
- Copperhelm Works
- Cor Aelin
- Coral Sea Enclave
- Coral Throne
- Coralhaven
- Coralindë
- Coralspire
- Court of Silent Bells
- Court of the Coral Crown
- Court of the Drowned Moon
- Court of the Nine Nereids
- Court of the Whale Road
- Cowriegate
- Cradle of the Slow Leviathans
- Crannog Sunk
- Crow's Nest Down
- Cryobot Landing
- Crystal Palace of the East Sea
- Curon Bell Tower
- Currentspire
- Cuttlebone Cairn
D: 39 names
- Damascus Sulcus Plume Town
- Dappled Court
- Davidson Seamount Reach
- De Profundis
- Dean's Blue Hole Below
- Deep Colony Marianas Ridge
- Deepholm
- Deeplab Cousteau
- Deepstar Ring
- Deepwatch
- Deepwatch Station Nautilus
- Deepwater
- Delmarith
- Delphin's Leap
- Delphinia
- Delphinium Below
- Derwent Under Ladybower
- Dexamene
- Diatom Glass
- Dilmun Shallows
- Dinas y Môr
- Dioscurias
- Diving Bell Parade
- Djuphamn
- Doggerland Below
- Dolphinsgate
- Dome City Aquilon
- Doris Deep
- Doto's Sound
- Driftglass
- Drowned Valley Chapel
- Drownhold
- Drownmaw
- Drughol Pits
- Dulse Market
- Dunwich Below
- Dwarka
- Dynamene
- Dypvik
E: 26 names
- Earle Reef Sanctuary
- East Pacific Rise Works
- Ebbfen
- Ebbgate
- Eddyhaven
- Eelby-in-the-Mud
- Eelgrass Commons
- Eelmere
- Eione
- Elarion Below
- Emberdeep
- Emden Platform
- Enalia
- Enalios
- Enceladus Plume Works
- Enceladus Southpole
- Enki's Cistern
- Epidaurus Below
- Erato Reach
- Eudora Shelf
- Eulimene
- Eupompe's Stair
- Europa Camp One
- Eurybia's Seat
- Eurynome's Throne
- Evermere Sound
F: 16 names
- Fabbriche di Careggine
- Faelmarin
- Fangwater
- Fathom-le-Deep
- Fathomgate
- Figurehead Square
- Floodmark
- Flotsam Wharf
- Foamgarth
- Foghollow Below
- Fomorian Towers
- Fondale
- Forge of the Vent Smiths
- Forum of the Seven Swells
- Fringing Reef Row
- Fundo do Mar
G: 45 names
- Gakkel Ridge Outpost
- Galápagos Rift Outpost
- Galatea's Court
- Galathea Depth Platform
- Galene
- Galileo Regio Shaft
- Ganymede Brine Layer
- Garden of Slow Anemones
- Garden of the Glass Sponges
- Gardens of the Last Light
- Garsecg
- Gaslamp Trench
- Gate of the Returning Tide
- Ghostlight Hold
- Ghulk's Ledge
- Giant Clam Square
- Gillrake Fort
- Glasswater Bay
- Glaukonome
- Glaukopolis
- Glaukos
- Glowspire
G, continued
- Glubina
- Gorgonian Walk
- Graakh-Tor
- Gran Carro
- Graveyard of Galleons
- Great Barrier Hold
- Great Blue Hole City
- Great Glass Promenade
- Gristle Shoal
- Grotto of Blue Lanterns
- Grotto of Coral Thrones
- Grotto of Drowned Stars
- Grotto of Echoes
- Grotto of Pearls
- Grotto of Sighing Shells
- Grotto of Silent Bells
- Grotto of Silent Tides
- Grotto of Sunken Bells
- Grotto of the Nine Currents
- Grotto of the Pale Whale
- Grotto of Whispers
- Guaymas Basin Farm
- Gyre Hold
H: 51 names
- Habitat Aquarius
- Habitat Ballard
- Habitat Cerulean
- Habitat Conshelf
- Habitat Fathom
- Habitat Halocline
- Habitat Helgoland
- Habitat Marinelab
- Habitat Meridian
- Habitat Nautilus
- Habitat Perigee
- Habitat Sadko
- Habitat Tektite
- Hadal Hold
- Hadalhaven
- Hadopelagos
- Halia
- Halimede
- Halkyone
- Halkyonis Nest
- Halls of Nine Tides
- Halls of Sunken Song
- Halls of the Coral Queen
- Halls of the Drowned King
- Hallsands
H, continued
- Halocline Gate
- Halopolis
- Halosia
- Halosydne
- Halyssa
- Harbor of Ships That Fell
- Harbor Without a Shore
- Havfrue Hall
- Havsbotten
- Hearth of the Black Smokers
- Heezen Fracture Platform
- Helike
- Hellenic Trench Works
- Heracleion
- Hermit's Shellmarket
- Herring Bourne
- Hippokampeion
- Hronrad
- Hudson Canyon Habitat
- Hy-Brasil
- Hycean Colony Thalia
- Hydra's Reach
- Hydrolab Nine
- Hydrolab Twelve
- Hydropolis
- Hydrothermal Haven
I: 14 names
- Ianeira
- Ice Shell Elevator Town
- Ichthyopolis
- Ikhtiandr Outpost
- Illuvane
- Ilyssane
- Iridelle
- Ironclad Arcade
- Ironscale Bastion
- Isobath Station
- Istana Laut
- Ithamere
- Ithilmar Reach
- Izu-Ogasawara Node
J: 4 names
- Java Trench Colony
- Jellybell Drift
- Jetsam Row
- Juan de Fuca Array
K: 43 names
- Kai Hohonu
- Kaiko Node
- Kaikoura Below
- Kaitei Toshi
- Kallianassa
- Kalyazin Belfry
- Kanaloa's Rest
- Keelhaven
- Kekova Below
- Kelp Cathedral
- Kelpcrown
- Kelphaven
- Kelpmoor
- Kelpshadow
- Kelvin Reach
- Kêr-Is
- Kerguelen Plateau Outpost
- Kermadec Hold
- Ketos Deep
- Khazreth Rift
- Kilstiffeen
K, continued
- Kingdom of the Kelp Forests
- Kings Fathom
- Kitezh
- Klymene Deep
- Korallenburg
- Korallion
- Kota Bawah Laut
- Kraken Mare Floor
- Kraken's Keep
- Krillbloom
- Krullspine
- Kumari Kandam
- Kuo-toa Deep
- Kuril Trench Depot
- Kyanopolis
- Kymaera
- Kymatia
- Kymatolege
- Kymodoke
- Kymopoleia
- Kymopolis
- Kymothoe
L: 41 names
- La Chalupa Lagoon Lab
- Labyrinth of Brain Coral
- Lagoon Crown
- Lagoon of Mirrors
- Lakebed Lyceum
- Lampreyhold
- Langarrow
- Lanternfish Deep
- Lanternspire
- Laomedeia
- Laurentian Deep Habitat
- Lemuria
- Lethowsow
- Leucothea
- Leviathan's Rest
- Library of Drowned Charts
- Ligeia Mare Landing
- Lighthouse of the Lower Dark
- Lighthouse That Faces Down
- Limenopolis
L, continued
- Limnoreia
- Limpet Regis
- Limpet Stair
- Lion City of Qiandao
- Lir's Hall
- Little Dabbling
- Llys Helig
- Locathah Shoals
- Loch Floor Village
- Loihi Seamount Base
- Loki's Castle Vent Works
- Lomea
- Longgong
- Loom of the Kelp Weavers
- Lorasëa
- Lost City Vent Colony
- Lough Neagh Halls
- Lower Ebbing
- Lowtide
- Lyonesse
- Lysianassa
M: 62 names
- Madinat al-Bahr
- Maelstrom Gate
- Makara Deep
- Mami Wata Court
- Manannán's Road
- Manganese Flats
- Mangrove Root Town
- Mantaglide
- Mardale Green
- Mare Profundum
- Margaritis
- Mariana Colony
- Mariana Reach
- Maristhene
- Marivenne
- Market of Unstrung Pearls
- Market Sunkley
- Marlinpoint
- Marlow-under-Wave
- Marmennill Deep
- Maury Channel Depot
- Mawgate
- Mediano
- Meeresgrund
- Melicertes Hold
- Melite
- Meltwater Plenum
- Menez Gwen Station
- Menippe's Gate
- Menouthis
- Meravelle
M, continued
- Merenpohja
- Merethuil
- Merfolk Spire
- Merhaven
- Meridian Deep
- Mermaid's Rest
- Merrow Hollow
- Merrowmere
- Mesopelagos
- Meteor Deep Ring
- Midnight Deep
- Milwaukee Deep Platform
- Mirenaë
- Mirror of the Moonless Sea
- Mirrormere Under
- Mizzenmast Tower
- Mji wa Bahari
- Moananui
- Mobilis in Mobili
- Mohns Ridge Platform
- Mologa
- Monterey Canyon Base
- Moon Jelly Lanterns
- Moonpool Junction
- Morghast Trench
- Motu Lagoon
- Mu
- Much Wading
- Mudford Weir
- Murkspire
- Musselmere
N: 43 names
- Nacrehaven
- Nagaloka
- Naiathel
- Nan Madol Below
- Nansen Basin Outpost
- Narwhal Cairn
- Nausithoe
- Nautilus Base
- Nautilus Port
- Nautilus Spire
- Neapcross
- Neapolis Below
- Necropolis of Whalebone
- Nemertes
- Neptuna
- Neptune Station
- Nereia
- Nereid Colony
- Nereidia
- Nereopolis
- Nereus Colony
N, continued
- Nereus Deep
- Nereus Station
- Nerine
- Nerites Reach
- Neritic Quarter
- Nesaia
- Neso
- New Rapture
- Nine Steeples
- Ninety East Ridge Array
- Nirivane
- Nixenhold
- Nixhold
- Njordhaven
- Nöckhaven
- Nodule Field Seven
- Noonlight Lagoon
- Nudibranch Gardens
- Nun's Cradle
- Nuvalis
- Nyai Roro Kidul's Court
- Nymarra
O: 31 names
- Oarfish Colonnade
- Observatory of the Inverted Sky
- Occator Brine Works
- Oceanopolis
- Oceanus Prime
- Octopus Garden
- Okeanopolis
- Old Adaminaby
- Old Halfeti Minaret
- Old Shipden
- Old Winchelsea
- Olokun's Hall
- Oloriel's Shallows
- Olous
- Ondariel
- Ondinaire
- Ontario Lacus Platform
- Ophyrra
- Orca Sound
- Orchard of Pearl Trees
- Oreithyia
- Oriluun
- Orvaleth
- Ostrakon Deep
- Ostreion
- Otohime's Palace
- Outpost Diamantina
- Outpost Horizon
- Outpost Molloy
- Outpost Vityaz
- Oysterspire
P: 56 names
- Palace of Coral Thrones
- Palace of Ten Thousand Pearls
- Palace of the Four Dragon Kings
- Palace of the Sea King
- Palaemonia
- Palaimon Deep
- Palau Deep
- Palmshadow Lagoon
- Panopeia
- Patala Below
- Pavlopetri
- Pearlhold
- Pearlspire
- Pebblecourt
- Pelagia
- Pelagorra
- Pelagos Prime
- Pellumine
- Perlenstadt
- Pherousa
- Philippine Trench Terminal
- Phorkys Deep
- Pike King's Court
- Pillars of Pontos
- Plankton Veil
- Plummet Station
- Pneumatic Quarter
- Pontia
P, continued
- Pontopolis
- Pontoporeia
- Pontus Deep
- Poompuhar
- Porcupine Plain Depot
- Porphyra
- Porpoise Run
- Port Royal Below
- Porthole Parade
- Porto Profundo
- Portunus Gate
- Portus Julius
- Poseidon Base
- Poseidonia
- Poseidonopolis
- Potosí of the Reservoir
- Précontinent Three
- Pressure Dome Seven
- Proteopolis
- Proteus Colony
- Proteus Sound
- Proto
- Psamathe
- Puerto Abisal
- Puerto Rico Trench Base
- Punga Mare Outpost
- Pwyll Crater Borehole
- Pycnocline Platform
Q: 3 names
- Qalupalik Warrens
- Quennelith
- Quenoril
R: 35 names
- Rainbow Vent Colony
- Raja Ampat Below
- Ran's Court
- Ranheim
- Rapture
- Raspfin Warrens
- Ratnakara
- Ravenser Odd
- Rayhold
- Reaver's Sump
- Reedking's Hall
- Reefcrest
- Reefhold
- Reefwatch
- Regnum Undarum
- Reimerswaal
- Reliquary of Anchors
- Reliquary of the Lost Fleet
- Rendtooth Ledge
- Reservoir Steeple
- Reykjanes Ridge Yard
- Riftdeep
- Rifthold
- Riftspire
- Riverbed Row
- Rivet Row
- Rockpool Terraces
- Romanche Gap Ring
- Ross Shelf Habitat
- Ruins of Cold Ys
- Rungholt
- Rusalka Deep
- Ryūgū
- Ryugu-jo
- Ryujin's Palace
S: 115 names
- Sable Bank Below
- Sadko's Court
- Saeftinghe
- Sahuagin Warrens
- Sahul Deep
- Saint Brine's
- Salacia's Veil
- Saltby-on-the-Shelf
- Saltmarch
- Saltspire
- Saltwick
- Salvage Exchange
- Samabaj
- Samphire Edge
- Samudra Mahal
- Samudrapura
- Sanctum of the Blue Flame
- Sandbar Steps
- Sandcastle Keys
- Sant Romà de Sau
- Sao's Reach
- Sargasso Deep
- Sargassum Roof
- Sathuriel
- Scallop Terraces
- Scourfin
- Sea Elf Enclave
- Sea Elf Hold
- Sea Lily Fields
- Sea Turtle Terraces
- Sea Wyrm's Hollow
- Seafan Arbor
- Seafloor Colony Anthem
- Seagrass Meadows
- Seahold
- Seahorse Paddock
- SeaLab Delta
- SeaLab Sigma
S, continued
- Second Ocean
- Sedna's Reach
- Selkie Cove Below
- Selunara
- Serpent Deep
- Seven Pagodas of Mahabalipuram
- Shaelune
- Shallowmere
- Sharkwatch
- Shell Fracture Harbor
- Shellhaven
- Shicheng
- Shingle Cross
- Shinkai Platform
- Shoalmarket
- Shoalwick
- Shrimp Lantern Quay
- Shrine of the Turning Shell
- Silfra Below
- Silthaven
- Simena
- Sinkhole Vale
- Sinking Halls of Ys
- Sinkwater
- Siren's Reach
- Sirena Deep Colony
- Sirenhold
- Sirenopolis
- Sirothiel
- Skarrith Maw
- Skopelos Deep
- Skylla's Strait
- Slackwater Reach
- Slitherdark
- Smokerspire
- Snake Pit Base
- Sobek's Reach
- Sodden Parva
S, continued
- Sonar Point
- Sous-les-Flots
- South Sandwich Terminal
- Speio
- Spindrift Crown
- Spinecoil
- Spongehaven
- Springtide Reach
- Squidhold
- Sskarth Burrows
- Stair of a Thousand Fathoms
- Stairway of Falling Snow
- Starfish Cross
- Starfish House
- Starfish Shallows
- Steam Vent Crescent
- Steeple Awash
- Stoa of Tethys
- Sub Undis
- Sublimnos
- Submerged Arcology One
- Substation Kelvin
- Sunbeam Shoal
- Sunda Deep Habitat
- Sunda Shelf City
- Sunda Trench Reach
- Sundaland Ruins
- Sunken Aqaba
- Sunken Phanagoria
- Sunken Selsey
- Sunkenhold
- Sunlit Shoals
- Sunshaft Gardens
- Surfline Steps
- Surgecrown
- Sverdrup Gyre Array
- Swellhaven
- Sybaris Below
- Sylmarra
T: 106 names
- Tangaroa Deep
- Tanglereef
- Tarnbottom
- Tehom
- Telchinis
- Telegraph Cable Town
- Temple of the Lantern Mother
- Temple of the Unbroken Wave
- Terraces of Green Dusk
- Terraces of the Patient Reef
- Tessamar
- Tethyopolis
- Tethys Base
- Tethysia
- Thalassaria
- Thalassia
- Thalassine
- Thalassodromos
- Thalassokratia
- Thalassopolis
- Thalwen
- Tharp Ridge Observatory
- Thaumas Gate
- The Abyssal Court
- The Benthic League
- The Benthic Reach
- The Bone Reef
- The Brine Lake Palaces
- The City of Bells
- The Cold Seep Gardens
- The Coral Citadel
- The Deep Sanctum
- The Drift Cities
- The Drowned Bazaar
- The Drowned Court
T, continued
- The Glass Sponge Cathedral
- The Hadal Senate
- The Hanging Reefs
- The Inverted Towers
- The Kelp Kingdom
- The Lightless City
- The Marine Snow Fields
- The Midnight Assembly
- The Nacre Throne
- The Pearl Exchange
- The Pearl Palace
- The Pressure Court
- The Silent City
- The Sunken Spire
- The Sunlit Confederacy
- The Tideless Capital
- The Trench Republic
- The Twilight Parliament
- The Undersea Vault
- The Whale Road
- The Whalefall Cities
- Thera Macula Lake Town
- Thermocline Terrace
- Thetis Base
- Thetis Reach
- Thonis
- Thoosa
- Thousand Lanterns of the Shelf
- Throkk Shelf
- Throne of Ten Fathoms
- Thurivael
- Tidal Heat Commons
- Tidebell Minster
- Tidegarth
- Tidehaven
T, continued
- Tidepool Town
- Tidewick
- Tiefenburg
- Tiger Stripe Harbor
- Tír fo Thuinn
- Tír na dTonn
- Tirvessa
- Titan Methane Docks
- Tolling-on-the-Seabed
- Tonga Station
- Tonga Trench Outpost
- Tower of the Upward Rain
- Trench City
- Trench Station Ballard
- Trench Station Copernicus
- Trench Station Hubble
- Trench Station Kepler
- Trench Station Piccard
- Trench Station Piccard II
- Trench Station Vescovo
- Trenchspire
- Trenchtown
- Triaina
- Trident Base
- Trident Hall
- Tridentspire
- Triton Citadel
- Tritonia
- Tritonium
- Tritonopolis
- Tubbataha Deep
- Turquoise Shallows
- Turtlehaven
- Twenty Thousand Leagues
- Twilight Reach
- Tyno Helig
U: 9 names
- Umi no Miyako
- Undaria
- Under-Ice Europa
- Undertide
- Undertowhold
- Undomiel Deep
- Urbs Submersa
- Urchin's Rest
- Urchinhold
V: 28 names
- Vaelithra
- Vaitarani Deep
- Val Ondrine
- Valhalla Basin Borehole
- Varuna's Court
- Vashti's Grotto
- Vault of Sighing Tides
- Vellamar
- Vellamo's Hall
- Venilia
- Venomreef
- Vent City
- Vent Colony Ashadze
- Vent Colony Endeavour
- Vent Colony Turtle Pits
- Vent Station Pele
- Vent Station Prometheus
- Vent Station Vulcan
- Venthaven
- Verdigris Wharf
- Vilarinho da Furna
- Villa Epecuén
- Ville Engloutie
- Vineta
- Vodyanoy Hall
- Volkhov Below
- Von Damm Vent Outpost
- Vrakmaw
W: 18 names
- Walsh Ledge Outpost
- Warmwater Wharf
- Watatsumi Hall
- Waterline Village
- Waverest
- Weddell Ice Colony
- Weir's End
- Well of the First Wave
- Wellenheim
- Wetherby-under-Water
- Whalehaven
- Whalesong Cairn
- Whelkmarket
- Whirlpool Gate
- Wrackham
- Wrackhold
- Wreckhaven
- Wyrmroost Deep
Y: 7 names
- Yemoja Deep
- Yonaguni
- Yonaguni Terrace
- Yonggung
- Ys
- Ysmeril
- Ysolmere