Keystone

The Keystone is a ziggurat that lies in the exact center of Tohra-Kren. The site itself is the source of the perpetual magic that allows the Great Vault to exist as a desert, and of the magic that bathes the city in artificial sunlight. The Keystone was built by Thri-Kreen workers, and enchanted by the great Druid Tik’tik, and the other Druids who helped create the Great Vault.