Su Sterru, The Chasm Of Golgo

In the collective imagination of the inhabitants of Baunei, the chasm of Golgo, “Su Sterru”, has always represented the unknown, and there are many legends around the mysterious chasm, the most important being the one of “San Pietro e Sa Serpente”. Nowadays, the chasm is a bona fide tourist attraction, a “Natural Monument” since 1993, which attracts thousands of visitors, to the point that “Golgo”, the name of the entire plateau, is now perceived by many as the name of the chasm.
A mistake regarding the name of the sinkhole name was also present, up until the fifties, on the old maps of the Military Geographical Institute (IGM, the best topography in Italy) in which “Su Sterru” was marked with the name “Cratere Vecchio” (“Old Crater”). That was because up until then the chasm was unanimously considered the crater of a volcano that, millions of years earlier, had expelled the basalt flow that covers ample stretches of the limestone plateau. The mistake was only put right in 1957, when an expedition of Sardinian speleologists (belonging to the “Pius XI Group” and the “Nuorese Cave Group”) explored the chasm for the first time and found that after the first thirty metres, the layer of basaltic rock gave way to limestone. Early explorers of “Su Sterru” discovered a karst abyss karst formed by rainwater erosion. Upon collapsing, the basalt “cap” reopened a karst well tens of millions of years old.
The first to descend into the chasm was the speleologist Bruno Piredda, but 150 metres of rope proved insufficient to reach the bottom. For the second attempt, a young architecture student with a passion for caving, a 22 year old from Nuoro belonging to the “Nuorese Cave Group” called Umberto Pintori volunteered and, at 10.30 am on 25 July 1957, was able to reach the bottom of “Su Sterru”. Subsequent measurements established that it was one of the deepest single span chasms in Europe: 280 metres down. Since then, descending down the sides of “Su Sterru” is a “must” for lovers of caving, and many caving groups have come specially from all over Italy to challenge the legendary chasm. One of these associations, the “Faenza Caving Group”, organised an expedition in 1978 and, on that occasion, also allowed the descent down the vertical shaft to be made by an avid caving enthusiast from Baunei: Paolo Muggianu, twenty-six at the time, the first local to have had the courage to face the mysterious “Su Sterru” sinkhole.