Estadio Ciudad de Lanús – Néstor Díaz Pérez, also known as La Fortaleza, is a football stadium in Lanús, Argentina, and home ground of Club Atlético Lanús. The stadium holds 47,090 people and was built in 1929. In September 2010, the club started construction on a roof for the local stand, which has since been completed. Several other works were completed in 2014, these additions consisting in a new changing rooms, a press conference room, an official club shop, a highly competitive gym, a café for club members and a secondary school behind the stadium.