Caerphilly Castle is a medieval castle located in Caerphilly, Wales. It was constructed between 1268 and 1271 by Gilbert de Clare, a powerful Welsh nobleman, to defend against the Welsh rebellion led by Llywelyn ap Gruffudd. The castle is notable for its unique concentric design, with a series of defensive walls and moats surrounding the inner keep.

The castle was attacked several times during its history, including during the Welsh Revolt of 1400 and the English Civil War in the 17th century. After the Civil War, the castle was abandoned and fell into disrepair until the 18th century when it was restored and used as a private residence. It was later acquired by the government and is now managed by the Welsh heritage agency Cadw.

Today, Caerphilly Castle is a popular tourist attraction and one of the largest castles in Wales. Visitors can explore the extensive grounds and interior rooms, including the Great Hall, the castle kitchens, and the spiral staircase leading to the top of the tower. The castle also hosts various events throughout the year, including medieval reenactments, outdoor concerts, and art exhibitions.