St Quentin's Castle crowns Castle Hill in the village of Llanblethian near Cowbridge in Vale of Glamorgan, Wales, built in the late 13th century to defend against Welsh uprisings. The imposing fortress features twin-towered gateway and substantial curtain wall remnants attributed to English nobleman Gilbert de Clare in the early 14th century. Set at a bend in the River Thaw with naturally defensive slopes, the castle commands fine regional views and retains information boards detailing its construction and heritage significance. Managed freely by Cadw with public access, it represents a fine example of medieval castle architecture in South Wales.