The tubes forming the viaducts, rest upon two abutments and three piers, called respectively the Anglesea abutment and pier, the Carnarvon abutment and pier, and the Britannia or central pier, built upon the Britannia rock in the middle of the straits, which gives name to the bridge. The Anglesea abutment is 143 feet 6 inches high, 55 feet wide, and 175 feet long to the end of the wings, which terminate in pedestals, supporting colossal lions on either side, 25 feet 6 inches in length, 12 feet 6 inches high, and 8 feet broad, carved out of a single block of Anglesea marble.