Avenc M-35

On 26 to 30 March 1970 a team from the SIE of the CEA explores the Forat de Montcortès (98 metres) and the Forat del Vicenç (-10 metres). Later, on 6 and 7 March 1976, another SIE team in which some of the members of the previous team take part, explore in the serra de Peracalç, between the estany de Montcortès and Peracalç, three caves of (-30 metres, -11 metres and -7 metres) depth respectively, which they name Forats de la Grata no. 1, 2 and 3; this information remains in the SIE archives but nothing about it is ever published. Very probably they correspond to one of the many holes explored by the GEB in this sector.

In 1980 the GEB begins a series of explorations on this flat area that lies to the N of the roca de Perauba and to the W of the dolmen de Perauba and which the GEB calls pla del campament because it is the spot where they set up camp during the explorations; these would last until 1988. Later they return in September 1994, in July 1995, when they accompany the archaeologists from the department of history of pre-capitalist societies and social anthropology of the UAB, and they return again in November 1999. Over the course of these years, the forest mass has grown considerably, which also complicates the location of the caves.

The cave was known since 1981 but it is not surveyed until 30 October 1988.