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Terramorphous Peak is an area in Borderlands 2, accessible only from Thousand Cuts, and only once you have accepted the You. Will. Die. (Seriously.) mission. It does not have a Fast Travel station. To enter Terramorphous Peak, first enter Slab Town in Thousand Cuts. Down a small walkway is a cave with a mysterious stone barrier and an altar that requires eight Eridium to proceed. Once the Eridium has been placed on the altar, the stone barriers will part and Terramorphous Peak can be accessed.

Terramorphous Peak is home to Terramorphous the Invincible. When entering the map, Terramorphous can be found by walking straight ahead and past a bridge where you'll see vending machines and the New-U station in an area below, then dropping onto a hole at the end which has a platform that will open automatically. Re-spawning at the New-U station means players have to either walk all the way around to the Thousand Cuts entrance, or drop down onto a lift that will shoot players up, providing a shortcut back to Terramorphous, however, the elevator's reset time is very slow.