3291: Entrada Tres
San Antonio 30T 446611 4801430 (Datum: ETRS89. Accuracy code: G) Altitude 94m
Length 704m Depth 46m
Area position

Updated 7th January, 1st July 2018

The third entrance to Invisible Cave, site 3283. The description and survey for the shaft has been incorporated into that site's account and survey, but photos can be linked to below. Entrada Tres was discovered and partly explored in the summer then linked to the cave below in the autumn of 2009.

The entrance is up on the heavily vegetated side of a valley, with a number of depressions.

A 15m pitch narrows near the bottom before breaking out into the rift. This has proved awkward to pull gear up. The pitch lands on a steep slope of rubble. Up slope ends at a tiny passage in the right wall and straight down the slope chokes. However, just off to the right, in tall passage, a step over a lip meets a 4m pitch down to a rubble slope and 2m climb down the side of a boulder to a small chamber that chokes straight ahead. To the left a short, but steep, bouldery slope intersects a cross rift that needs investigating in both ends at high level. A ladder climb down the rift (p5) encounters "station 14" in Invisible Cave and a bouldery climb down to the stream.
Down-slope from the entrance pitch, just before the second drop on the right, is a step up on the right. This enters passage that turns back and passes a display of tree roots and a short, slippery back-and-foot traverse over a pit. The narrow passage deepens forcing a 6.5m pitch, belayed from stal in the roof bedding. At the base, a shuffle through pools leads to a squeeze past a small column into a decorated chamber with holes in the floor. Down to the left is a chamber with an aven and 2m deep bouldery drop.

References: anon., 2009c (summer logbook); anon., 2009d (autumn logbook); Corrin Juan, 2010
Entrance pictures: 2009
Underground pictures : 2009
Video :
Detailed Survey : yes
Line Survey :
On area survey :
Survex file : yes
Passage direction rose diagram: 1/7/2018