Grotta di Su Mannau

Grotta di Su Mannau lies near Fluminimaggiore in south Sardinia, where the underground river Placido has carved a network of tunnels and chambers. The guided route follows the cave’s left branch, with stalactites, stalagmites, pools and a tall final chamber to see along the way. Metal walkways, stairs and viewing platforms help you move through the accessible sections. Inside, temperatures stay around 20°C, so bring a light jacket even on a hot day above ground.

How the cave was formed

Grotta di Su Mannau is in the territory of Fluminimaggiore, in south Sardinia. Its origins go back more than 500 million years, and water still shapes the cave today. The system extends for about 8 kilometres and divides into two branches, each formed by a stream.

The visitor route follows the left branch, carved by the river Placido. This accessible section includes an archaeological room as well as chambers shaped by geological processes. The full tunnel network is much larger than the route open to visitors.

What you see along the route

The cave’s rooms vary in scale, with delicate formations set against immense chambers. Stalactites and stalagmites create intricate shapes and colours, while the river and pools bring water into the underground scenery. One chamber rises to an especially striking height.

Metal walkways, stairs and small viewing platforms make it possible to move through the visitor route and look into the larger spaces from different angles. A guide is available in Italian and French, and audio guides cover multiple languages. The English narration is brief, so visitors relying on it should expect less detail than the live Italian explanation.