Mysterious Cave

The Mysterious Cave is a two-floor cave in Dahlgur Oasis in Act II of Diablo III.

It can spawn in one of the two watered-in nooks in Dahlgur Oasis, both of which extend south from the open parts of the zone. The southern one is east of the entrance from the Ruined Cistern, and the northern one is east of the "neck" that connects the north and south halves of the zone. The cave can only be opened by helping Zaven the Alchemist fend off a few angry Wraiths, after which he opens the cave and lets the player enter. This area must be explored in order to complete the achievement Nooks and Crannies.

The cave may contain a Mysterious Chest which contains the Liquid Rainbow, an item needed to enter the fabled Whimsyshire. Note that neither Zaven nor the chest are guaranteed to spawn. It may also spawn a Cursed Spire in which you have to fend off 5 waves of zombies. This is required in order to complete the Cursebreaker of Caldeum achievement.

In Adventure Mode, there is a chance "Clear the Mysterious Cave" will be one of the five Act II bounties. If so, Zaven is guaranteed to spawn.