The Hercules Grotto, long considered endless, is a legendary place. The Greek hero Heracles is said to have rested here before doing his eleventh labour. This consisted in picking the golden apples in the garden of the Hesperides. According to ancient Greek authors, this is said to have been in the ancient city of Lixus (near today's Moroccan city of Larache).
Although this story can also be located in the realm of legends, it is considered certain that the cave was already in use in the year 6000 BC. was settled. It was rediscovered in 1878 and, due to its remoteness, was often used by Moroccan couples for a tryst. The cave was then opened to the public in 1920 and declared a national heritage site in 1952. After a brief closure, it has been open to the public again since 2004.
The bizarre formations inside the cave can be explained by the fact that the Berbers who live here cut blanks for the grinding stones of their rotary mills from the walls.