Structures known as Irish Round Towers, built from the late 8th-12th centuries CE, dotted the island in medieval centuries. The only monumental stone buildings in Ireland to come before the Normans invaded, the towers used to be thought to function as lookouts for Viking invasions. Historians now ascribe less martial functions to the buildings, thinking they perhaps either functioned as royal chapel/status symbols or, more likely, as church belfries. The entrance to the towers is above ground – whereas that might seem like a defensive move to help monks scurry away from incoming mauraders – the above ground entrances probably were to give better architectural support. The tower shown here (the tower at Clondalkin) dates from about 790 CE, so these buildings certainly could last! (P.s., the Clondalkin tower is about 27 meters and is the only one left that has its original cap!)