Heroes' Hole

The Heroes' Hole or Hero's Hole is a dungeon in the mountains west of Trinsic, near to the Shrine of Honor It appears in Ultima VI and in the  Super Nintendo port of Ultima VII.

Description
Heroes' Hole earned its name due to its history as a testing ground for the knights of Serpent's Hold, who would frequently journey to these caves to prove their prowess in battle. Within its depths lay numerous perils, including a vicious hydra and, for a time, a rogue necromancer who had sought shelter within its lowest caverns. Those who dared plumb its lowest levels would even find that the caverns interlinked with those of the distant Dungeon Despise.

Ultima VII (SNES Port)
While the Heroes' Hole did not make an appearance in Ultima VII for the PC, it did appear in the SNES version of the game. There, it contained a valuable piece of equipment known as the Scale Boots, a piece of footwear constructed such that those who wore them could even withstand walking over active patches of lava.

Solution
For a solution to the dungeon in Ultima VI, see: Heroes' Hole Solution For a solution to the dungeon in The Ultima 6 Project, see: The Ultima 6 Project Heroes' Hole Solution