It's about time Wales had its first OpenCache and this is it!
Chepstow castle is generally accepted to be the earliest stone-built castle still surviving in Britain. The Great Hall was started in 1067, the year after William the conqueror was crowned King of England. The castle building was planned by William FitzOsbern, the king's steward and master builder, who wielded power along the southern Welsh Marches.
The castle is owned by CADW and is well worth visiting at any time of the year. There is plenty of further information about its history, opening times and charges to be found on-line.
If you park in the lower car park, near the main castle entrance, you'll be a two minute stroll from the cache location. It's a 6" x 3" x 2" click-lock box with the usual few trinkets, logbook and pencil.