The first level of the "sonic" game i'm working on is a subversion of the ancient ruins level trope. The civilization that built these structures is certainly alive, even if it may have "fallen" at one point.

Iguanopolis is the capital of the Iguana Kingdom. Its patron diety, and the patron of all Iguanas, is Marduk, the sun god. Since the fall of the Predator Empires, the kingdom has rapidly modernized. The Iguanas are skilled masons, and their eccentric building style remains popular.