Mustatils are prehistoric monuments made of sandstone walls which are found in northwest Saudi Arabia.

[1][2] Over 1,000 mustatils, clustered in groups of 2–19, are spread out across a ritual landscape covering 200,000 square kilometres.

Excavation of one mustatil funded by the Royal Commission for Al-'Ula revealed a chamber at the center containing fragments of cattle skulls, but no remains from other parts of the animals; they are believed to be evidence of a previously unknown cattle cult.

[4] Radiocarbon dating of the skulls revealed that the mustatil, and maybe the others, was built between 5300–5000 BCE, during the Holocene Humid Phase, a time when the area was a grassland that went through frequent droughts.

This would make the mustatils one of the oldest-known large-scale ritual landscapes in the world.