Grotta di Santa Barbara

Grotta di Santa Barbara is a chamber inside the San Giovanni mine in Iglesias. Discovered by miners in 1952, it is known for its high hall, full-height stalactite columns, dark tabular barite and a small underground lake, within Lower Cambrian host rocks.

Why it matters

The cave’s position inside the San Giovanni mine helped preserve its formations until miners encountered it during underground work in 1952. SardegnaTurismo describes its host rocks as about 500 million years old and highlights the cave’s tabular barite coating. The cave joins a natural geological record with the industrial history of the Iglesiente.

What to notice

A hall more than twenty-five metres high is lined with stalactite columns and honeycomb formations. Dark brown tabular barite appears between waxy limestone and yellow silicified dolomite. Aragonite formations and a small underground lake add further features to the chamber.

Context and history

The cave was discovered in 1952 during work in the San Giovanni mine and was opened for guided visits in 2016. Mining in the area has a much longer history: the operator’s account describes workings from Roman and Pisan periods, while industrial extraction expanded after the Gonnesa Mining Company received a concession in 1867. The San Giovanni mine ceased activity in 1998 and is now part of the Sardinian Geomining Historical and Environmental Park.