Whatever name you call it it’s helpful to remember to avoid the problems common with city-under-the-sea stories (as addressed in this TV Tropes page).
Can’t be arsed to care about that. Story’s not for publication; it’s an Xmas present. I just wanted a name that sounded nice.
Aquaregia. See if anyone gets it.
Bikini Bottom
Shellville
Mile deep city
Drink
Brackland
Aqua Velva? Aqua Vulva?
Yeah… They do…
Actually, there is a series of UK kids’ books written by Gillian Shields called Mermaid — Sisters of the Sea, which is possibly aimed at small girls ‘Meet Misty, Ellie, Sophie, Holly, Lucy and Scarlett’. Very* British* small mermaidens. To avoid copyright infringement you might avoid: ‘Oceania’, ‘Coral Kingdom’, and ‘Giant Kelp Forest’.
When searching as above, I ran across another lady I’d never heard of, Miss Henriette Mertz, a Chicago patent attorney who in the '60s and '70s studied Homer and concluded the Odyssey went North…
Moreover, Mertz believed that Odysseus faced Scylla and Charybdis when he arrived at the Bay of Fundy in Nova Scotia. Mertz also proposed that the Argonauts travelled across the Atlantic Ocean, down the east coast of South America, past the mouth of the Amazon and Rio de Janeiro to the Rio Plata of Argentina. From Rio Plata, Jason went to the altiplano of Bolivia and to Tihuanaco where the Golden Fleece was located.
“Mertz actually proposed in her book Atlantis: Dwelling Place of the Gods that the eastern section of the United States, from the Mississippi and Ohio rivers east, was the Atlantis of Greek myth.”
and… Did the ancient Chinese know British Columbia as the land of the fir tree ?
On the other hand, she was a code-breaker during WWII, which argues greater intelligence than most of us; yet possibly even the ranks of cryptoanalysts have their share of eccentrics.
Sorry, Wiki link.
Bathyopolis would be the Greek rendition of “Deep City”, plus it includes the entirely happenstance association in English of “bath” meaning being immersed in water.
Yoinks ago I wrote about a sea-centric culture (a thalasocracy) and named their only city Thalassas. IIUC, it’s Greek for “the sea”, not “a sea” but “all that salty water out there”; I’ve seen several versions for the transliteration.
Glub
Fishtopolis?
Interesting - this fellow posits that Troy was somewhere in Celtic Britain over the tin mines in Cornwall.
Burfillia.
Mu
Lemuria
Falias, Glorias, Murias and Finias were cities of the Tuatha na Danaan, & Danu was the goddess of craftsmanship.
Fomor
Ybrik
Glub Med.
Mariana City.
Aquaria
Seasurfia
Pacifica
Brine
Aquamarina
Oceane
Something related to Pontus, Nereus, or Proteus, perhaps?
Since you are casting Posiedon as the enemy, perhaps Caenis would be apt.
Wow. Cornwall has a habit of inspiring fey thinking… [ Actually, though nice countryside; and wherever you are you are never more than 20 miles from the sea: it’s as prosaic as the rest of Europe now — it’s quite safe to take a coach-ride through Transylvania now, I hear ].
Such theorizing seems to have found it’s summit in Divus Julius, with the idea that Jesus Christ is merely an aspect of Julius Caesar; but an imaginative person seeking wealth could possibly mix up the Arthurian legend, with the Troy legend, and the Breton myths of Ys, and Lyonesse, and Christ visiting Cornwall along with Joseph of Arimathea, and throw the Norse myths in there.
If only to annoy the Welsh.
No, no. Glug. Then all the little cities around it would comprise the Glug Archipelago.
Also, Langerhans, located i the Islets of Langerhans.