Elvas

Elvas is a municipality, former episcopal city and frontier fortress in easternmost central Portugal, in the Portalegre district of the Alentejo. It lies about 200 kilometres east of Lisbon and only eight kilometres west of the Spanish fortress of Badajoz, on the Madrid–Badajoz–Lisbon railway. Everything about the town follows from that position: it carries the largest bulwarked dry-ditch fortifications in the world, and the aqueduct that supplied the garrison strides across the valley on arches for several kilometres.