Chepstow Castle is the oldest surviving stone fortification in Britain. It was built on the the instructions of the Norman lord William fitzOsbern, soon to be made Earl of Hereford.
The castle was started in 1067, and was to become the southernmost of King Edward I's "iron ring" of castles built along the English-Welsh border in the Welsh Marches.
Today Chepstow Castle is open to the public, and since 1984 has been in the care of Cadw. There are special events held often in the castle and visitors are able to walk along the battlements and into Martens Tower.