Finding one of the Twin Cache should assist in finding the other.
Blockhead Cache was a cache I had placed near this location. Recent development in the area appeared it would destroy Blockhead so I removed it. However, the development did not destroy the area so I replaced Blockhead with a new cache. This new cache is placed in memory of Blockhead. Will require a bit of searching but once found this will assist you in locating its twin cache, Twin #1: In Memory of Plugged.