The Castle can be visited
Beaumaris Castle

On the Welsh island of Anglesey, Beaumaris Castle is a ruin that stands as an example of medieval fortress architecture. Although never fully completed, it is considered a representation of 13th-century English castle building, particularly due to its complex concentric defenses and surrounding moat.
History+
The construction of Beaumaris Castle was initiated by Edward I of England to secure his dominion over Wales. It was the last castle designed for him by the master builder James of St. George. Unlike other fortresses built by Edward, Beaumaris was conceived as a water castle, encircled by a wide moat protecting its outer curtain wall. The castle remained unfinished.
Source: Wikipedia · Licence: CC BY-SA 4.0
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 53.2649, -4.0898