The Grand Union Canal links Birmingham to London with a waterway which is 145 miles long and contains 166 locks. This cache is one of a series to be found along or close to the Hertfordshire/Buckinghamshire stretch of the canal.
This cache is placed alongside the lock at Great Seabrook . You will have to cross the lock gates to access the cache. While you are there, you can see the remains of two side ponds which were created to conserve water, which was always a concern on the Grand Union. The lock was first emptied into the side pond and when the water levels were equal, the paddles were closed and it was then emptied into the cut below. This saved half a lock of water. Going up, you also saved half a lock by filling the lock from the side ponds at first, and then from the cut above. All clever stuff!
You are looking for a small square tupperware type container. As with all these canal caches, please take care near the water, especially if caching with kids. Make sure that no muggles see you with the cache and please do a good re-hiding job. Thanks.