The Burnt World of Athas

Ancient tablets found in a wrecked silt skimmer herald the coming of Athasian Warforged.

As the name suggests, this is a compilation of types of plants found on Athas. This resource gives descriptions of various plants: trees, cash crops, and even dangerous, carnivorous plants. Geographical locations where the plants grow are given as well as any other relevant information on the plant.

The Good and the Green; An Examination of the Athasian Halfling Culture in the form of a letter from Brandobaris, flailing adventurer of Ogo, to his dear friend, the elven priest and preserver Disnomos.

Another ancient unofficial article found in the web archives:

According to the Draji religion, a faith propagated by centuries of state sponsorship, King Tectuktitlay is the supreme temporal and spiritual authority of the cosmos, a kind of perfect incarnation of the spiritual forces of Athas. The Draji are taught that their King is the creator of all life and is responsible for investing the world with order and purpose. Unlike their neighbours in Raam, the people of Draj largely believe what the Moon Priests have taught them and they look upon Athas as world with their own King as its necessary centre. In Draj, as in Gulg, it is the state religion which dominates Draji identity and outlook, making it one of the more stable cities of the region, and certainly the most arrogant.

Tales of the corrupt races, Trolls, Wemics, Pixies, Goblins, the abominations of the Arcane Apocalypse.

An ancient unofficial article from the depths of the internet:
The Dray, the draconic race who dwell far beneath the scorched surface of Athas, owe their fearsome form to a transformation wrought ages ago upon the band of humans who then served under Dregoth. However it was not only the bodies of his people that the Dread Lord saw fit to alter to his liking, but also their hearts and minds. This was achieved long before the physical transformation, when he fashioned for them a new religion, one which places himself at the centre of a cosmic drama in which they would play a vital part.

Words and Language of the Athasian Elf.

Outpost Kaprak was a small, remote storehouse and waypoint for House Malaxi, a once-great merchant house that fell on hard times.

Thanks go to Kamelion for compiling this comprehensive list of location references in Dark Sun products released by Wizards of the Coast.