Avenc de les Alzines

The first exploration was carried out in 1962 by the GES del CMB.

It is not very clear when the first exploration that gave access to the current Sala Fantasma was made, but we have evidence of explorations carried out in the late sixties.

Between 2006 and 2007 a group of archaeologists from the Grup de Recerca del Quaternari del SERP de la Universitat de Barcelona, who also carried out similar work at the avenc Gran de les Alzines, with the help of an excavator completely emptied the doline where the entrance of the pit opens, razing all the vegetation for quite a few metres around. This causes the opening of two new entrances that are left in a rather unstable situation.

On a visit carried out in December 2009 it is observed that one of the entrances has been covered by the sediments that had accumulated around the doline and that have been dragged by the rain. On another visit carried out in June 2011 it is confirmed that the sediments dragged by the rain have definitively sealed the two entrances opened by the archaeologists' work; likewise the doline is gradually recovering its former appearance. During the following years the only access to the cavity is again through the primitive entrance, although its original appearance has been quite modified.

Following the unblocking work carried out in recent years at the nearby avenc Nou de les Alzines, initially opened by the aforementioned archaeologists, members of the EspeleoCorb in 2018 unblock again the other two entrances of the avenc de les Alzines.

After 14 years without being able to access it, finally on 16 January 2022 access is achieved again to the Sala Fantasma (previously it had been referred to as Pou de la Revolució). The floor of this chamber has been covered with a butyl rubber sheet, to prevent the entry of infiltrations from filling it with mud again and settling it anew.

In 2023 a new unblocking at the Sala Fantasma allows access to a new large chamber, it is the Sala dels Templers, the name given to it from a curious cross-shaped formation on the wall.

The exploration of this new chamber has made possible the carrying out of various climbs, some of which end a few metres from the outside.

In the unblocking, exploration and various attempts at surveying the cavity that did not come to fruition, many people belonging to various Groups have participated, among whom we can mention Joaquim Castaño (†), Francesc Romera, Pedro Valdepeñas, Lluís Domingo, Pere Miralles, Jaume Clemente, Francesc Alarcón, Manel Peloche, Jordi Coma, Xavier Galiana, Laura Besolí, David Prat, Judith Bertolí, Subi Gudanyol, Gorka Basterra, Tomás Garcia, Sandra Oliveras, Mikel Rodriguez, Jordi Mire, Laura Moreno, Alan Ruiz, Javi Pardo, Susana del Valle, Carlos Miranda, Ignasi López, Josep Subirana, Xavier Aliaga, Cesar Jiménez, Jordi Navarro, Montse Mañosa, Brauli Torres, Xavier Ruiz, and Manuel Ruiz.

In January 2024 Juli Serrano (SIE-CEA) and Francesc Rubinat (ERE-CEC) carry out a new survey of the cavity.