Abandoned Cave
Map: Abandoned Cave

You enter or fall into the small Abandoned Cave from Abandoned Caves above. The attached map marks the return transition near (4,7), leading back to Abandoned Caves. From there, take an exit into Hollowgrave Tunnels.
We have not confirmed a separate puzzle, quest or unique reward on this lowest level. Its map is mainly useful for finding your way back after dropping through a pit.
