Tresviso Caves Project

Tresviso Caves Project Gazetter

T145D: Segura 2

(Castillo IV)

Area:Mazarrasa Mines
East, North:360484, 4785476 (nearby)
Coordinate Quality:GPS
Long, Lat:-4.7174977815932, 43.209150212898 (map)
Elevation (m):1837
Length (m):110
Depth (m):-1
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 leading to an obvious small spoil heap containing the entrance to Segura 2. Continuing on the main track leads to the Segura 1 entrance. (Segura 1 should be revisited and surveyed as potentially it may bypass the current collapses in Pozo Castillo and provide access to the main cave.)


The driven mine adit is 2m x 2m


The driven mine adit is 2m x 2m and continues for the first 30m in knee deep water. After another 20m the passage bends to the south and continues for another 50m, passing a flooded section on the right with a wooden gangway. The passage then meets the main Castillo junction

Left and straight leads to the main way on into Pozo Natacha,
Left and up (via wooden ladder) leads to the upper Pozo Natacha series,
Straight on leads to the Pozo Castillo entrance pitches,
Right and down leads to the main way on into Pozo Castillo.

FT16 Castillo III Entrance 3 by 3 leading to P20.
At less than 10m a snow plug has come down on the left hand side of a P40 that rejoins T145.
At 5m on the P40 is a winch platform.
At 15m a system of mines connects to Segura 1 (Castillo V).
At 20m a series of mine galleries has a connection with the crawls in T145 (around 700m)
One of the mines goes back up 30m to a natural crawl 50cm by 30cm reconnecting with the mines in Sequra 2 (Castillo IV).
FT16 has a vocal connection with FT17 at 1.2m.


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