The City of Ssitherai (without the serpent maw gates, it's Kalabuto from Serpent's Skull).
Ssitherai is an island that was apart of the Continent of Lybia but had broken away when part of the Continent of Lybia was claimed by the ocean. Peopled almost exclusively by serpentfolk, the island is a vertiable paradise next to the desert expanse. Once populated by humans, the Serpentfolk enslaved the humans and brought in beast races (kobolds, gnolls, ratfolk, and catfolk for example) for more slaves. Ssitherai is also the name of the Central City of Ssitherai. From here, the Serpent Folk has built an incredible city. Few humans, especially Hellenes, had the temerity to create a colony on Ssitherai. Erpetos is the Hellenic Colony. So far, it's existence is hidden from the Serpent folk. So far.