Ye Olde Survey Monuments (GC45CC) is a travelling geocache that is owned by outforthehunt. The cache moves around the country and you could be looking for a specific survey monument, pillar, surface block, rivet or bolt.

It’s a little like trigpointing (see ) except you can only log ones where the owner of the cache has randomly moved the YOSM cache to it.

It moves a couple of times a month, though, so there’s always plenty to go at.

So far, I have attempted the following Survey Monuments in the series :

Unfortunately, the big-wigs at have decided that this kind of cache is no longer welcome, so YOSM has been archived.