Caldicot Castle is an extensive stone medieval fortress in southeast Wales, built by Norman earls of Hereford beginning around 1100 near the site of a former Saxon stronghold. The castle's most distinctive feature is an unusual semi-circular tower housing a dungeon and upper chamber, with solid masonry filling intermediate levels. Constructed from the early 12th century onwards, the oldest sections date to around 1170, including the circular keep at the northwest corner and thousand-foot curtain walls enclosing the inner ward. After centuries of royal and noble occupation, the castle was purchased by antiquarian J.R. Cobb in 1855, who undertook extensive restoration returning it to medieval grandeur. Today, Caldicot Castle is surrounded by a 55-acre Country Park, with free entry offering visitors access to one of Wales' most important heritage treasures.