Conímbriga is one of the largest Roman settlements excavated in Portugal, that was classified as a National Monument in 1910. Located in the civil parish of Condeixa-a-Velha e Condeixa-a-Nova, in the municipality of Condeixa-a-Nova it is situated 2 kilometres (1.2 mi) from the municipal seat and 16 kilometres (9.9 mi) from Coimbra (the Roman town of Aeminium). Conímbriga is a walled urban settlement, encircled by a curtain of stone structures approximately 1,500 metres (4,900 ft) long. Entrance to the settlement is made from vaulted structures consisting of two doors (one on hinges), and that at one time was defended by two towers. The walls are paralleled by two passages for water removal, channelled to excavations, in order remove water infiltration from the walls.