The 1st-century Roman aqueduct of Segovia is simply breathtaking. Constructed around AD 50 during the reign of the Roman Emperor Trajan out of some 200,400 granite blocks, the aqueduct was made without concrete and stands due to the equal balance of forces. When in use, it carries water from the River Frio to the city of Segovia over a distance of 16km (ten miles). The portion of the aqueduct that is above ground is 728m (2388ft) in length and consists of 165 arches, each over 9m (30ft) high.
