Cool city names for setting of my book?

Since it is a city-state sort of thing, perhaps something like "The Citadel" or "The Sanctuary", or "The Havens", akin to city names "The Bruges" in Belgium or "The Vatican". Based on the fact that you cannot leave, I prefer "The Citadel". There is also a name already in existence on Balearic Island of Menorca, Ciutadella, which is very evocative. (We've gone on holiday to Menorca a few times and have visited the city.) Perhaps even Ciutadella de Nova. Good luck with your book. ~ ~ ~