18 by 18 bottomless pit

screen shot of bottomless pit

On first glance, this looks like a "chunk loader fault" : a transient condition where a section of map (a chunk) doesn't appear properly client side (minecraft has a client-server setup even playing single player since a couple of versions ago).

If you place a torch at the edge of the "hole" to provoke a lighting update, this will often prompt the client to attempt to reload the chunk from the server. On SMP you can try relogging. Attempting to enter the chunk will cause your position to stutter, making movement almost impossible.

Note : this is a sneaky way of prospecting ore by sight 😉

Duplicate of MC-2545. Will update the affected version.