What is the capital of Atlantis?

Apparently the capital of Atlantis was Atlantis. The earliest known discussion of Atlantis is in Plato's writings, essentially for the purpose of contrasting it with the city-state of Athens.

However, since Plato's works are in the Public Domain by now, if you want to write your own story about Atlantis and call its capital city Georgis, no one can stop you.