The Cueva de Sangre (Cave of Blood) is located about 2 km east of the El Duende group, it has more than 3 km of tunnel running underneath a small hill. The cave has four entrances, two of which had been blocked with rubble as at Cueva de El Duende. The west entrance appears to have been the principal entrance used by the ancient inhabitants of Dos Pilas. A small building was built above this entrance, the function of this building must have been linked to the use of the cave itself. A stone wall enclosed both the cave entrance and the building itself. Preclassic ceramic fragments were found inside the Cueva de Sangre.