Grotta di Su Mannau, Natural cave system in Fluminimaggiore, Sardinia, Italy.
Grotta di Su Mannau is a cave system in Fluminimaggiore that stretches for about 8 kilometers underground beneath the limestone. The interior contains crystal-clear lakes, waterfalls, and rock formations shaped by water flow and erosion throughout its long existence.
The cave system formed roughly 540 million years ago through natural karst processes as water dissolved the limestone. Archaeological evidence reveals that people living in pre-Nuragic times used it as a sacred underground space.
The place held spiritual meaning for early Sardinians, who viewed underground waters as sacred and left behind clay oil lamps as evidence of their rituals. Local people today recognize it as part of their island's subterranean heritage.
Visitors can join guided tours lasting about one hour that cover 500 meters of the left branch with elevated walkways. The paths are built above underground water features, making the walk safe and manageable for most people.
The cave waters are home to Stenasellus nuragicus, a type of shrimp found nowhere else in the world. This tiny creature has adapted perfectly to life in complete darkness and the isolated underground environment.
GPS coordinates: 39.40750,8.49347
Latest update: December 6, 2025 17:44
Sardinia preserves traces of human settlement across thousands of years. The island presents prehistoric cult sites including sacred wells and burial mounds that show ancient rituals. Nuraghe towers from the Bronze Age still rise above the landscape, while Roman theaters and Punic temples mark later civilizations. Underground tombs carved directly into rock lie hidden in the hills. Mountain villages carry modern wall murals that tell political and social history. The coastline offers small coves with turquoise water and white pebble beaches between limestone cliffs. Caves along the coast display stalactites and underground lakes. Inland, canyons with tall rock walls cut through remote areas. Natural springs emerge from bedrock, lighthouses stand on headlands overlooking the sea. Abandoned mining complexes document industrial history, while protected islands and coastal reserves provide habitat for marine life and seabirds.
Porto Flavia
10.8 km
Piscinas
15.2 km
Pan di Zucchero
11.5 km
Temple of Antas
1.6 km
Grotta di San Giovanni
13.9 km
Piscina Irgas
11.9 km
Cathedral of Santa Chiara
11 km
Grotta di Santa Barbara
13.9 km
Castello di Salvaterra
11 km
Chiesa di Nostra Signora di Valverde
11.7 km
San Francesco
11 km
Walls of Iglesias
10.8 km
Spiaggia di Buggerru
7.9 km
La Purissima
10.9 km
Giardino Montano Linasia
10.7 km
Chiesa di San Michele
11 km
Chiesa di Sant'Antonio Abate
10.4 km
San Domenico
10.9 km
Chiesa delle Anime Purganti
11.1 km
Electra Cafè Letterario
11 km
Miniera di Su Zurfuro
1.9 km
Santa Maria delle Grazie
11.2 km
Spiaggia di Portixeddu
7.7 km
Spiaggia Fontanamare
14.9 km
Scivu
12.1 km
Portu Banda
11.5 km
Town hall of Iglesias
11 km
Spiaggia di Cala Domestica
10.5 kmReviews
Visited this place? Tap the stars to rate it and share your experience / photos with the community! Try now! You can cancel it anytime.
Discover hidden gems everywhere you go!
From secret cafés to breathtaking viewpoints, skip the crowded tourist spots and find places that match your style. Our app makes it easy with voice search, smart filtering, route optimization, and insider tips from travelers worldwide. Download now for the complete mobile experience.
A unique approach to discovering new places❞
— Le Figaro
All the places worth exploring❞
— France Info
A tailor-made excursion in just a few clicks❞
— 20 Minutes