You’re no fun anymore! 
:: sighing ::
Fine. I have dispatched a company of the flying monkeys to pummel you with spitballs.
If it could be described as lying adjacent to (or in the vicinity of) the Nether-regions (Dis), you could get away with Paradis.
Seattle?
Colors are always good for this sort of thing. “Aquamarine” is obvious, but I also like “Azure”.
Or how about “Tarshish”? It’s the biblical city (actual location unknown) that Jonah was running to before he got et by a whale, so you’ve got your marine allusions.
Wet.
Coralina
Nothing could be finer.
Y’all can keep talking about it, but I have decided to go with Tethys, slightly modified.
Because not all intelligent species would tend towards living in cities. In the merfolk’s case, it’s because their environment would hinder that kind of development.
It’s an inherently silly discussion, but those are my speciality, so I’ll respond.
This is a work of fiction I am writing upon request as an Xmas present. It’s about the requestor’s fantasy visit to the city of the merpeople, set ina world I’ve written about before. The basic conceits imply either magic or a world with different physical laws than the real one. I don’t see why you’d expect sociology to work the same when physics clearly doesn’t.
“Tarsis” is a pretty major city in the Dragonlance world, though.
Do the mermen (and merwomen) speak English? Or do they speak a foreign language in the story? This is an important distinction. If they speak English then they could call it something like Wateria, Oceana, Oceania. If they speak Mermish then they could call it Loubalouhoop or whatever makes sense in their local language.
Or you can call it Atlanta! /futurama
I like Nereidia.
By the previously established rules of this universe, the fantasy characters have their own languages. When speaking with persons who speak a foreign language they use a translating device which is programmed to ignore certain words, proper names among them.
How about Noctiluca? It’s a genera of oceanic algae, some species of which, at least, are bioluminescent when disturbed. Perhaps the town can use them as a light source.
Kyanos.
Looking up Homer + wine-dark, I discovered that this was the Greek ( then ) for blue.
‘A long, long sigh
For the cold strange eyes of a little Mermaiden,
And the gleam of her golden hair.’…
sigh No-one reads Arnold anymore…
Will you feel better if I recite “Dover Beach” from memory?
Never mind. On the one hand, you’d know you have a fellow Dover fan. On the other hand, it’s freaking “Dover Beach,” what with the image of ignorant armies clashing and all. And you know that girl left him the next morning.
Depending on their political philosophy, you may want to consider the name Rapture.
I like the idea of something with “Nauti-” in the name just because it’s a good watery prefix.
Or Algaeria (don’t kill me!)