Shaft of El Llest (Mura) located in the range of L’Obac, near Coll de Boix. This is one amongst 163 cavities that are reported in the area of Sant Llorenç del Munt i l’Obac. The common origin is the water solubilisation of the concrete of the conglomerate rock that starts in previous crevices. The shaft of El llest is 56 m deep and it includes a large internal room. Additional shafts in the area are that of Castellsapera with a wide mouth, Sant Jaume de la Mata, L’Espluga which is the deeppest one and the shaft of Daví that shelters a bats colony in winter.
[photo Jordi Badia]