Imposing Chepstow Castle perches atop a limestone cliff overhanging the river, guarding the main river crossing from England into South Wales. It is one of the oldest castles in Britain – building started in 1067, less than a year after William the Conqueror invaded England. The impressive Great Tower dates from this time and includes bricks plundered from the nearby Roman town of Caerwent. It was extended over the centuries, resulting in a long, narrow complex snaking along the hill.
There are plenty of towers, battlements and wall walks to explore and lots of green space in between. Keep an eye out for the primitive latrines extending over the river and for the oldest surviving castle door in Europe, a massive wooden barrier dated to before 1190 and used in the main gateway until 1962.
A cave in the cliff below the castle (sadly, no longer accessible to the public) is one of many places where legend says King Arthur and his knights are napping until the day they're needed to save Britain.
Once the entire town was wrapped in fortified walls, bolting it to the castle. Parts of the 13th-century Port Wall, edging the western side of the town centre, can be seen from the Welsh St car park and near the train station. Chepstow's main street, High St, passes through the Gate House, the original city gate, which was restored in the 16th century.