The gallery is 2,130 metres long, out of which 1,200 can be visited.
It is a very beautiful and amazing underground space because of its length, its vast lakes and the wide variety of formations, amongst other things. The first reference to Las Maravillas Grotto in history dates from 1850. It was opened to the public in 1914 and became one of the first tourist caves in Spain. In this phreatic cave there are many formations - stalactites and stalagmites create beautiful rooms. Some of the most significant ones are: Los Brillantes, Gran Lago and Los Desnudos, without forgetting Las Conchas, Esmeralda and Cristalería de Dios.