Updated 19th February 1999; 18th January 2004; 31st October 2007; 30th June 2018

The entrance is situated 15m higher up the valley than Cueva del Humo (734). A sandy ramp degenerates to an area of loose boulders. A 8m pitch is followed by a 10m pitch in quick succession. A loose, bouldery area leads to a 19m pitch with an unsurveyed, draughting passage. To the right a low crawl leads to a traverse to the top of a 26m pitch. From the base a very high but narrow rift leads out to pitches of 17m and 9m in a clean washed streamway. A tight passage requires some traversing to an 8.4m pitch. A calcite-floored chamber has an obvious route to the left which ends at an aven. An insignificant crawl pops out into the streamway which has debris up the walls with boulders and sand. Fifteen metres downstream enters a large aven and continues in boulders. The stream cuts down in the floor whilst the caver stays at high level on the right. A gour pool is passed on the left. At a calcite area a ladder eases a slippery descent of some 5m.

The stream continues in the trench with traversing above when an area of dropped roof slabs, covering the trench (Vino Collapso) is met. Walking over the slabs and continued traversing leads to a place where the higher level becomes impossible and tackle is necessary to continue at stream level.

Upstream, Top of the World is a large aven with large boulders at its base. The passage narrows upstream to Walk Like an Egyptian, where a large pyramid-shaped block lies across the passage. The streamway widens, cutting a trench at this point, with debris. Routes diverge at various levels, leading to a high route with a flat ceiling with much debris. At Apache Junction the 2 routes of significance lead off. The one to the west has excellent straws from the roof which lowers to a crawl which may or may not continue. The passage to the east enters an area of calcite flows which closes down in crawls and small chambers with avens. A small rift is impassable. There are a number of avens with good echoes.

Cuenca cavers in the Asociación Espeleologica Conquense Lobetum have linked Cueva del Humo (734) with Torca de Esquimadera (739) to form the Sistema del Humo with a combined length of 2200m.

References: anon., 1989 (logbook); Corrin J, 1990; material in file; anon., 1993a (survey); anon., 1994c (survey and photo); García José León, 1997 (survey); Valero Enrique y Soriano Ángel, 2007; León García José, 2010 (Volume 1 and Volume 2) (survey and photos)
Entrance picture :
Underground picture(s):
Detailed Survey : from anon., 1993a (AEC Lobetum):
high res system plan  low res system plan
high res projected section of Esquimadera  low res projected section of Esquimadera
Line Survey :
On area survey :
Survex file : Esquimadera : Humo (Coordinates altered to fit ETRS89 datum, April 2014.)
Passage direction rose diagram: 30/6/2018