The tower was rediscovered during routine maintenance work in 1912, and excavations below the Half Moon Battery revealed the extent of the surviving buildings. Several rooms are accessible to the public, although the lower parts are generally closed. Outside the tower, but within the battery, is a three-storey room, where large portions of the exterior wall of the tower are still visible, showing shattered masonry caused by the bombardment of 1573. Beside the tower, a section of the former curtain wall was discovered, with a gun loop which overlooked High Street: a recess was made in the outer battery wall to reveal this gun loop. In 1912-1913 the adjacent Fore Well was cleared and surveyed and was found to be deep, mostly hewn through the rock below the castle.