Why was Tanis closely examining the map? What was notable about it?

Tanis was closely examining a map to see if he could find a way out of the city. Some of the things that were notable about the map was that the structures themselves, especially those at the heart of the city were fantastically beautiful, more beautiful than Tanis had ever seen, and the strangest thing was, that despite having never been there, Tanis swore he recognized the place.