Elvas is a Portuguese municipality, an episcopal city and frontier fortress of Portugal, located in the district of
Portalegre in
Alentejo. It is situated about east of
Lisbon, and about west of the Spanish fortress of
Badajoz, by the
Madrid-Badajoz-Lisbon railway. The municipality population was 23,078, in an area of . The city itself had a population of 15,155 .