Headsman's Cave is a small cave below Headsman's Hill in Fable, Fable: The Lost Chapters, and Fable Anniversary. Normally, it is only accessible if you duel Thunder in the quest Mayor's Invitation, during which Thunder and the Hero tumble over the cliff together. There is a Demon Door here which, conveniently, will open only once it sees you have defeated another Hero in combat. Once Thunder is finally defeated inside the cave, the Door will open, but it only serves as an exit to Gibbet Woods.