Estadio Ciudad de Lanús – Néstor Díaz Pérez, also known as "La Fortaleza" (The Fortress), is a multi-use stadium in Lanús, Argentina. It is currently used primarily for football matches and is the home ground of Club Atlético Lanús. The stadium holds 46,619 and was built in 1929. In September 2010, the club started building a roof for the local stand, and is now completed. Other several works are currently in progress, which consist of 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.