High in the skies over Kazakhstan, space-age technology has revealed an ancient mystery on the ground.

Satellite pictures of a remote and treeless northern steppe reveal colossal earthworks — geometric figures of squares, crosses, lines and rings the size of several football fields, recognizable only from the air and the oldest estimated at 8,000 years old.

The largest, near a Neolithic settlement, is a giant square of 101 raised mounds, its opposite corners connected by a diagonal cross, covering more terrain than the Great Pyramid of Cheops. Another is a kind of three-limbed swastika, its arms ending in zigzags bent counterclockwise.

Described last year at an archaeology conference in Istanbul as unique and previously unstudied, the earthworks, in the Turgai region of northern Kazakhstan, now number at least 260 — mounds, trenches and ramparts — arrayed in five basic shapes.