The Sertão Pattern is a natural monument located in western Pernambuco, Brazil. The pattern is created from perennial rainfall and flooding followed by long periods of drought. Experts are still studying how the pattern is created so precisely, and why it has only appeared in one location and not across the region in similar microclimates. Local lore asserts that the pattern was created by extraterrestrials, and the area is treated as a sacred visitation site for the supernatural.