Hidden away in north Shropshire, and on private land, is The Berth, a mid-Iron Age 'hillfort' of about 300 BC. The site has been claimed as the capital of the Welsh king Cynddylan, and as the Isle of Avalon, the burial place of King Arthur, though little archaeological work has been undertaken.
In plan, the fort is akin to a memorial ribbon, a smaller enclosure linked by a causeway to its larger cousin. The construction is not atop a hill, but upon marshland, and would have gained its defence by virtue of originally being surrounded by water. A sense of what the site may have been like is provided by the adjoining Berth Pool.