Royal Observer Corps Monitoring Posts are underground structures all over the United Kingdom, constructed as a result of the Corps' nuclear reporting role and operated by volunteers during the Cold War between 1955 and 1991.
In all but a very few instances the posts were built to a standard design consisting of a 14-foot-deep access shaft, a toilet/store and a monitoring room. The most unusual post was the non-standard one constructed in a cellar within Windsor Castle.