The main attraction of Aracena is the Gruta de las Maravillas (Cave of Marvels). The caves are located just below the hill where the Aracena Castle stands. The legend is that a boy was looking for a lost pig and stumbled onto the caves. The caves were opened to the public in 1914 and there is a circular route of about 1 km. There are about a thousand steps going up and down, so one needs to be physically fit to see the caves. The route takes about 45 minutes to see with a guide, who points out places of interest. The caves are of karstic origin and there are many places with low ceilings. One can see many pools of water that are dramatically lighted. After a group passes, the lights are turned off automatically because any light makes bacteria grow, which is a danger to the caves. There are many stalagtites and stalagmites and caverns which are very impressive. These caves are some of the best caves in Spain and one of the first to be opened to the public.
The caves have been used in movies such as Journey to the Center of the Earth and Tarzan in King Solomon’s Mines.