Updated 11th October 2011; 11th February, 28th April 2016; 23rd September 2018; 24th May 2021; 16th February, 14th November 2022

A dye test from Torca del Hoyón (567) was carried out in the 80's but without result, though possibly positive in Cueva del Comellantes (040). The entrance to the cave behind the resurgence is Cueva del Molino (0727).
According to Guy Simonnot (pers. comm. October 2011) it is likely that the flow in Molino (site 727) can be accounted for by Orcones and "the collector - Cantu Pasillo Encarmado." He continues, paraphrased, for cavities such as Vallina we may need to think about another source (resurgence) - which would suit me better geologically." Further details of this hypothesis are found on the Molino cave page.

   The water tracing in Cueva Vallina carried out at Easter 2015 gave a positive result at Cueva del Comellantes. A completely negative result was obtained at Molino. Details can be found on the Vallina page.
   Detectors placed at Molino and just upstream in the valley over Easter 2016 tested negative when optical brightener was successfully traced from site 4246 in the Torca del Hoyón depression to Comellantes in La Vega, Matienzo. (Photos below)

The site was dived at Whit 95 for about 50m to a tangle of line which appeared to have been laid from the downstream sump in the cave. The survey taken at this time appears to be wrongly orientated but has since been corrected. The site was redived at Easter 97 and line needs removing in order to connect it with the cave.

An account from Josep Guarro in the 2022 January, February logbook states,
We (Josep and José Miguel Castillo) went to Cueva del Molino on Easter 2004 invited by Rupert Skorupka, who was diving there on those days. ... He invited us to dive the 1st sump fo the resurgence in Cueva del Molino. I remember that we cleared all the old lines, and laid a new line from the entrance to the end of the sump, at the other side of it in Cueva del Molino (site 0727). But unfortunately we did not have time to survey it. (Photos below).

According to Simonnot G, 2016, P. Degouve dived through into Cueva del Molino (0727) in 1981. The water temperature on 23rd September 2017 was 10.7°C (Simonnot G, 2018).

Link to entry in the Cave Diving Sump Index.

Reference: Corrin J, 1990; Loriol B de, 1959 (survey); material in file; anon., 1995b (Whit logbook); anon., 1997a (Easter logbook); anon., 2011e (autumn logbook); Papard Philip, Corrin Juan and Smith Peter, 2014; Simonnot Guy, 2014; Simonnot G, 2016; anon., 2016b (Easter logbook); Simonnot G, 2018; anon., 2022a (January, February logbook); Simonnot G, 2022
Entrance pictures : yes : from Easter 2004 : wide angle : in high water : flood video (YouTube)
Underground picture(s):
Detailed Survey :
Line Survey :
On area survey :
Survex file : yes (Amended magnetic declination December 2013 to align with Eur79 grid and coordinates altered to fit ETRS89 datum, April 2014.)