Updated 22nd June, 13th October 2013; 23rd May 2015; 21st February 2016; 26th September 2023

   A small depression just up from the field edge contains a slope down to an open entrance into a bouldery chamber (with old shoes on the floor). The floor slopes down to 3m pitch between a large boulder and a solid wall. At the base, a delicate crawl down over boulders leads to the top of a second, similar depth pitch, down which water (in wet weather) drops. This pitch was dropped 4m in May 2013 to an open passage with a stream. Downstream, the walking-size passage lowers and meets a boulder choke within a few metres. Boulders have been moved around in this area but prospects at stream level don't look promising. Just back from here, up a narrow rift on the right, it is possible to push a camera into a cross rift that goes over the choke. This may be enterable after the inital rift up has been enlarged. Upstream, hands and knees crawling in water and silt soon meets a sump.
    Over the top of the second pitch a small, muddy, phreatic passage becomes smaller at a sideways squeeze then becomes a mixture of roomy crawling, walking and traversing as the sandy, phreatic higher level cuts across the streamway. The passage meets an unexplored crawl through a pool but this can be bypassed by climbing up to the higher level on the right. The cave soon becomes smaller and, after a sideways squeeze through a small pool, the route onwards is small around a left hand bend. The passage at this point appears to be gently rising and is about 20m east and 22m below the sink at site 2449.
   A possible continuation of the higher level heading downstream then east from the top of the second pitch has been explored, but only for 20m to a low dig with no noticeable draught.

   OBA detectors were placed in the stream in March 2015 when Leucaphor was placed in site 3886. No OBA was detected here but the trace proved positive in Jivero 1.
   Optical brightener was put in the stream on 13th February 2016 and detectors checked in various resurgences over the next few days in rising and falling flood conditions. The optical brightener came through at the Jivero 1 resurgence between 48 and 72 hours later. (The full details can be found here.)

Reference: anon., 2013b (Easter logbook); anon., 2013c (Whit logbook); anon., 2013d (summer logbook); anon., 2015b (Easter logbook); anon., 2016a (January, February logbook); anon., 2023c (summer logbook)
Entrance pictures : yes
Underground pictures : Easter and spring 2013 : summer 2013
Video : high level exploration (YouTube) : Down 2nd pitch (YouTube)
Detailed survey : 1:500 pdf : 1:500 pdf (summer 2013)
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.): Jivero 1 hydrological system