Museo Fortín Cuatreros, Military museum in General Daniel Cerri, Argentina.

The Museo Fortín Cuatreros occupies a late-1888 casa fortín, a defensive rooftop house built on the Estancia de Sansinena, at the corner of Alvarado and Avenida Plácida Pernici in General Daniel Cerri. Rebuilt from May 1974 by the Army and the Municipality, it recovered its mangrullo watchtower. Its rooms hold an archaeological collection, belongings of General Daniel Cerri, and displays on ranchos, gauchos, fortineros, pulpería and the 20th century, plus carriages outdoors.

The building was erected in late 1888 on land first owned by Ernesto Tornquist and later sold to the Sansinena family, becoming the Estancia de Sansinena. Such casa fortín or azotea houses were cheaper constructions serving as defensive units and shelter for the ranch hands. It was declared a National Historical Monument on 7 June 1944 by decree no. 14119, when a newspaper noted that little remained of its walls.

The museum keeps the sword and sash that General Daniel Cerri wore in the Argentine Army, donated by his children on 13 May 1933 to the town's historical museum. Exhibits also cover pulperías, gauchos and fortineros, and the first Noche de los Museos was held here on 20 March 2010.

The museum stands at the corner of Alvarado and Avenida Plácida Pernici in General Daniel Cerri, about 12 km from Bahía Blanca, and depends on the city's Instituto Cultural. It occupies the reconstructed fortín and its grounds, with the mangrullo lookout and open-air displays of carriages outside. Confirm current opening hours with the Instituto Cultural before travelling.

The fortín was declared a National Historical Monument in 1944, when a newspaper noted that "time had taken its toll on its walls" and almost nothing remained. The Provincial designation came later, in 1997, under Law 11918.