Hiere we are at the beginning of the aqueduct as it enters the historic part of Segovia. We're sitting in front of the building that would purify the water. This aqueduct was used to carry water from the Guadarrama mountains to the city of Segovia during Roman times up until the 1800s. It is no longer used, but it could function if need be. From the mountains into Segovia the aqueduct declines at 1% grade.