Diamondhead is a free city within the Salterri Heartlands.
It was originally built around the trade post for cliffhorn goats that AQUA founded, and the Islanders were the most prominent builders who suggested the creation of the city. The growth of Diamondhead has been sponsored a lot by the Silver Throne, and many foreigners have moved into the city, which expanded greatly when the Glazfell Hegemony aided its expansion by the founding of a second trade post, this one for fish.
Diamondhead's population still mainly consists of Islanders and Salterri, but also contains minorities of frosten berapi, tieflings and komola. The outer bounds of the city are closed off from the rest of Penoccident, and non-Komola citizens of the city that aren't otherwise specifically authorized for it are not allowed to leave by land, partly because of the dangers the inlands of Penoccident is known for, partly because the komola and Salterri are still not fond of the idea of strangers mucking about in their backyards.