Children of the Stones (1977)

Filmed at Avebury, this seven-part serial places its fictional village, Milbury, inside a real stone circle, and the stones loom over nearly every outdoor scene. An astrophysicist and his teenage son arrive to study them and find villagers who are unnervingly content, because the village's leader has found a way to harness the circle's power and strip away free will. It was made for children and is still often named among the most frightening things ever shown to them. The science-fiction explanation sits on top of a genuinely ancient landscape, and that pairing is exactly what makes it linger.