Roman Dam of Belas

The Roman Dam of Belas is a 3rd-century Roman barrier constructed to serve the city of Olisipo, located in civil parish of Queluz e Belas, municipality of Sintra [1]. The dam was constructed in the 3rd century, although it is unclear when it was abandoned [1]. The ancient ruins of the dam are survived by a central segment some 15.5 metres long, 8 metres tall and 7 metres wide, and reinforced by three buttresses [1]. The reservoir created by the dam warehoused approximately 125 cubic metres of water [1]. The channel from the structure extends 1,300 metres and is visible as it still intersects the more modern Águas Livres Aqueduct that was built over the old structures [1].