Tresviso Caves Project

Tresviso Caves Project Gazetter

FT16: Castillo III

Area:Mazarrasa Mines
East, North:360453, 4785449 (nearby)
Coordinate Quality:GPS
Long, Lat:-4.717872413615, 43.208901461422 (map)
Elevation (m):1830
Length (m):107
Depth (m):-75
Active Lead:
Survey Available:


Just past the obvious fenced mine area (Minas de Mazzarassa) on obvious track on the right, before the start of the switchbacks ascending to Pozo Castillo, leads along the east hand side of the Pozo de Andara (Lake Depression) . The track splits with the left hand route going to Segura 2 and the right hand route continuing to Segura 1. FT16 and FT17 are both located directly east and slightly above the Segura 1 entrance


Large open cavity


Castillo II (FT17) is a large entrance of 10m x 5m that leads to a 20m pitch, parallel to the FT16 entrance pitch and has a vocal connection at -12m. The bottom has not been explored but is assumed to be part of the FT16 entrance chamber.
Castillo III (FT16) is a 23m pitch down to a snow plug. At -15m a winch platform is met with a dangerous platform leading to the Castillo V (Segura 1) entrance. At the bottom of the pitch is a window back into Pozo del Castillo.
The pitch continues down over a snow plug, via a traverse of 17m (2017), to the head of a series of pitches down one side of the snow plug. A 7m and 12m pitch leads to a final 12m pitch / traverse under the snow plug.
A small climb down and up leads to an area of mine spoil with old wooden ladders on the floor. Following the passage for a further 15m leads to the final pitch of 12m. This lands in a small chamber with a sump. There is no way on.
Total length of passage explored and surveyed in this area was 107m and the cave reaches a depth of -75m.


L.S.D. (1981) T.C.P. (2017)