De Odieta

The pit opens along a joint trending 275°N. The entrance forms a small funnel-shaped doline in a layer of marl about 4 metres thick; beneath it continues a joint with fluted walls formed in Eocene limestone. At 48 m, windows are visible that open in the direction of the fracture and in opposite senses: one, with formations, narrows and prevents exploration, and the other ends in a clay plug. At about 56 m a lateral shaft opens in the direction of the joint that rejoins the main shaft 8 m lower. At 84 m the pit narrows to pass through a conglomerate layer about 6 metres thick. Beyond the conglomerate one emerges at the upper part of a chamber where a steeply sloping wall of flowstone is visible and in which a large window of very difficult access can be seen. Two drops of 4 m and 6 m place one at the maximum depth of the cavity, whose floor is formed by a clay plug. The walls are of nummulitic limestone with flutes.

In one of the windows located at 48 m there are formations. In the upper part of the chamber a steeply sloping wall of flowstone is visible.

Through a small hole located in the lowest part of the pit and at a clay-limestone contact, water seeps that falls from the rain directly from the entrance or along the flowstone wall.

Climb along the left bank of the ravine with a gentle slope. After about 15 minutes the path crosses the ravine and climbs steeply, zigzagging along the shady slope of Odieta. After about half an hour a path is reached; to the left the Foz formed by the river as it passes through the limestones can be seen. After about 15 minutes and after having crossed a small wood, a field with spikes opens to the right where the path fades. A pine wood is visible, at whose edge the doline of the pit in marls opens.