Hidden close(ish) to this cache's given coords on 25th August 2001 (a Saturday) was GC18BC - Tim's Number 2 - The Second Attempt. It survives as the UK's oldest remaining Puzzle cache. To find that one, first find GC177 and follow the instructions you'll find in that box.
However, to find *this* cache, you just have to look either side of it. Good luck!