AN-519

Great shaft of Añelarra, with a wide entrance that communicates through a series of pits of 15, 18, 7, 23 and 7 metres with a narrow, elongated meander at -110 metres over about 15 metres. After this meander there is a pit of 7 metres and, after that, another longer one of about 50 metres, which gives way to an enormous pit 222 metres deep named Extremist/El Extremista, with a large floor at -357 metres.

The large floor at -357 metres gives way to the great fossil canyon of the Añelarra System, fourth entrance that reaches a depth of -739 metres.