The capital of Florin is known as Florin City.
Florin is likely a fictionalized version of the Republic of Florence (now a part of Italy). The florin was a gold coin minted in Florence in the late Middle Ages and early Renaissance – fitting with the general setting of the movie. The Aruban florin is named after this coin. Aruba is ruled by the Dutch, who formerly used the guilder.
Guilder, the rival nation of Florin, is also likely named after a coin: the Dutch guilder.