The Caves of Hercules is an archaeological cave complex located in Cape Spartel, Morocco. Situated 14 kilometres (9 mi) west of Tangier, the popular tourist attraction is adjacent to the summer palace of the king of Morocco. The cave itself is partly natural and partly man-made. The man-made portion was used by Berbers to cut stone wheels from the walls to make millstones, resulting in the ridges visible on the walls in this photograph of the cave's interior.Photograph credit: Diego Delso