The Tulu are an evil and devious race, demonstrating the canny wickedness of Faustian devils and the perverse pleasures of hentai tentacle pornography.
A portmanteau of the words Architecture and Ecology, arcologies are megastructres that are built with an eye towards environmentally friendliness.
This really comes from an ancient Chinese novel. Imagine during the PCs' travels, they come to a place where the gender roles are completely reversed. What adventures will the PCs encounter in such a place?