The caves of su Mannau, in the territory of Fluminimaggiore, are a karstic complex 'sculpted' 540 million years ago that runs eight kilometres into the heart of the Iglesiente subsoil and is still 'alive', i.e. the limestone formations are in continuous evolution.

In the tour on suspended platforms that takes about an hour, you will advance through red shades of rock, waterfalls, and blue lakes, alabastrine and aragonite flows, stalactites, stalagmites and crystals. Also of interest are the 'archaeological hall', which was a pre-Nuragic and Nuragic sacred place where water worship was practised (as evidenced by several remains of oil lamps and votive vessels) and the Rodriguez Well, home to an impressive 7-metre column of stalagmites and stalactites.