It was built between 1381 and 1385 to protect the River Thames. It has a double bailey, the eastern side
having a tower in each corner and earth walls in between surrounded by a dry moat and accessed through the ornate gateway. The smaller western bailey has stone walls which are still at least half their original height with a tower in each corner and a wet moat on three sides. The entrance is through the eastern bailey on the fourth side. It is now in ruins with a more recent house inside the grounds but the gatehouse remains in good condition. The castle was besieged in 1554 and suffered damaged by cannon fire.