Sierra de las Quijadas National Park, National park in San Luis Province, Argentina.

Sierra de las Quijadas National Park covers 73,534 hectares in northwestern San Luis Province. Its centre is the Potrero de la Aguada, a bowl-shaped basin drained by the Arroyo de la Aguada, dry except after summer rains. Around it rise reddish cliffs, cornices and terraces of the El Toscal and La Cruz formations, laid down around 110 million years ago as river sediments and cut into stepped ledges and vertical fissures.

The park was created by national law 24015, passed on 13 November 1991 and promulgated on 10 December 1991, after a 1989 agreement between San Luis Province and the National Parks Administration. The province transferred 73,534 hectares to the national state by decree in 1999, accepted federally in 2006.

Near the park entrance lies a large Huarpe settlement with more than twenty pottery kilns or botijas. Fragments show thin-walled grey ceramics with even firing and incised double-line decoration. One kiln is prepared for visitors, shown with authorized guides.

The park welcomes visitors and offers guided tours to explore the landscape, with administrative services available in San Luis city. Plan for sufficient time to explore the different areas, as the size of the site means multiple days may be needed for a thorough visit.

The area preserves fossils of two pterosaur species, including one with specialized teeth forming a basket-like structure for filtering microorganisms. These prehistoric discoveries show that flying reptiles once inhabited the region.