Cova de l'Espluga

The galleries of the cavity are structured following the fracturing that cuts the conglomerates, mainly in a cross system NNE-SSW and ESE-WNW. The resulting direction of the cavity is approximately NE-SW, following the dip direction of the conglomerates.

We will distinguish five sectors in the description of the cavity:

1-Galeria del Pessebre, Galeria del Quincall and accessoria. These are the closest to the entrances of the cave. The galeria del Quincall is an elbow between two currently closed mouths, the gallery has dimensions of 10x5 metres. The main gallery is a long conduit of dimensions similar to those of the Quincall. Formerly the sediments occupied the section up to a height of 2 metres above the current floor but on opening the current entrance a clearing of the gallery was carried out. At about 200 metres from the mouth the accumulation of sediments forces progress through a narrow vaulted channel that forms the upper part of the gallery, the width can reach 15 metres. A low stretch of 50 metres, partially excavated, leads us to the confluence with the river. In this sector there are small accessoria galleries that move away from the main route: gatoneres del Francolí, l'Eixample and gatoneres de Can Palletes. The latter connect with the base of the shaft opened in the courtyard of Can Palletes, located on carrer St. Antoni and the only access to the cavity until the year 1957.

2-Diàclasis del riu -Somni d'una nit d'estiu- Font Major. Having found the river, in a N direction, the waters enter a network of galleries often flooded. Morphologically two well-delimited sectors can be distinguished. The initial and middle stretches are a network oriented N-S, with two or more parallel galleries linked by open E-W joints. They are narrow and elongated conduits, with bare rock and without sediments. The final stretch has developed taking advantage of the stratification, they are wide conduits with low vaults that lead to the Font Major after passing several stretches that are almost always sumped.

3-Galeria del Llac – Sala del pou de la Biela. The galeria del Llac is the continuation of the cave, going up the course of the underground river, from the previous bifurcation point, the gallery maintains sections of up to 5x3 metres. The depth of the water is variable, from a few centimetres to more than one metre. The course is very calm, often imperceptible. Some small conduits, full of fine sediments, converge coming from the S. The second of them (in the direction of progress) has recovered a certain dynamism from the construction of the dam, since the waters, when they reach the crest of the dam, produce a leak at the tail of the flooded zone that reappears through this gallery. Going up a small slope, we reach the chamber of the pou de la Biela, the largest in the cavity, with more than 15 metres of width, 35 metres of length and heights of 8 metres. The floor is covered with blocks fallen from the ceiling, in the centre of the ceiling opens the pou de la Biela, which constitutes an artificial entrance in this sector of the cave. At the NW end of the chamber is the sump that stopped the explorations until 1985. The current appearance has been modified since the construction of the dam with a wall 8 metres long and 3 metres high.

4-Galeria ERE and accessoria. At the bottom of the sump a short artificial gallery opens that connects with the bottom of the municipal pumping shaft, 21 metres deep. The galeria ERE has average dimensions of 5-6 metres of width and 3 metres of height and the river runs freely there; some blocks fallen from the ceiling are remarkable. Further on we find a network formed by the galeria ERE itself, l'afluent del Casal, la Bessona del fang and the so-called Primer Pis Fòssil. Since the construction of the dam, which raises the water level by about 3 metres, this whole stretch of gallery is usually flooded.

5-Galeria Carulla – La Maranya. It is the natural continuation of the galeria ERE, but with widths of 8 metres and upwards, whereas the height is around one metre, remaining in some points only 25-30 centimetres the distance between the water and the ceiling. In any case some holes in the ceiling of the gallery allow access to an old and higher one, divided into several fragments and which corresponds to the high levels of the Bessona del fang and of the Primer and Segon Pis Fòssil. As in the galeria del Llac, we also find tributaries coming from the S, filled by sediments.

The final conduits (la Maranya) are tangled due to the lack of perspective caused by the low height. The end is a muddy sump that becomes cloudy very quickly and that has made useless the attempts to force it with self-contained diving gear. This point is 65 linear metres from the Pou del Casal, which is a borehole of 18 metres to the water (25.7 metres total depth).

The cave is traversed by an underground river. In the galeria del Llac, the depth of the water is variable, from a few centimetres to more than one metre, and the course is very calm, often imperceptible. Some small conduits, full of fine sediments, converge coming from the S. The second of them has recovered a certain dynamism from the construction of the dam, since the waters, when they reach the crest of the dam, produce a leak at the tail of the flooded zone that reappears through this gallery. In the galeria ERE, the river runs freely. Since the construction of the dam, which raises the water level by about 3 metres, this whole stretch of gallery is usually flooded. In the galeria Carulla – La Maranya, the height is around one metre, remaining in some points only 25-30 centimetres the distance between the water and the ceiling. The end is a muddy sump that becomes cloudy very quickly.

Progression through the cave is conditioned by the presence of water and sediments. In the galeria del Quincall, formerly the sediments occupied the section up to a height of 2 metres above the current floor, but on opening the current entrance a clearing of the gallery was carried out. At about 200 metres from the mouth, the accumulation of sediments forces progress through a narrow vaulted channel that forms the upper part of the gallery. A low stretch of 50 metres, partially excavated, leads to the confluence with the river. In the Diàclasis del riu, the waters enter a network of galleries often flooded. In the galeria del Llac, the depth of the water is variable. In the galeria ERE, since the construction of the dam, this whole stretch is usually flooded. In the galeria Carulla – La Maranya, the low height and the lack of perspective make the final conduits tangled. The end is a muddy sump that becomes cloudy very quickly and that has made useless the attempts to force it with self-contained diving gear.