The Straining Tower at Lake Vyrnwy, Wales. 1885. Standing only 30 metres (98 ft) from the shore, the tower's purpose is to filter or strain out material in the water with a fine metal mesh, before the water flows along an aqueduct to Liverpool. The tower is built in the Gothic revival style and is 47 metres (154 ft) tall, 32 metres (104 ft) of which is above water. It's topped with a pointed copper-clad roof which has weathered to a lovely light green.