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Daemon's Crag in Pagan is surrounded by a lake of boiling lava, created by Pyros. There is no secure connection to the rest of the island, making the visit to it dangerous. Like islands, the Sorcerers' Enclave and the Obsidian Fortress are in the midst of it.
The Avatar cooled down a small part of the lake in Ultima VIII with a new river, enabling him to create a passage to the Sorcerers' Enclave.