Hidden beneath the giant limestone cliffs (tacchi) towering above Ulassai lies one of Europe’s most majestic underground monuments: the Su Marmuri Cave (Grotta di Su Marmuri). Its name, which translates to "marble cave" in the local dialect, immediately hints at its spectacular nature, welcoming visitors through an imposing arched entrance carved into the heart of the mountain.
Once past the threshold and down the steps leading underground, you enter a colossal cavern that stretches for nearly a kilometer. The path winds through massive galleries with ceilings reaching up to thirty-five meters high, where water and time have sculpted towering stalagmites and stalactites, as well as dramatic basin-like pools filled with pure water. A constant temperature of around ten degrees Celsius and the complete absence of natural light create a surreal, suspended atmosphere—a perfect sanctuary for one of Italy's most important bat colonies.
A visit to this subterranean wonder serves as the ideal springboard for exploring the extraordinary cultural and natural highlights nearby. Just a stone's throw away lies the art-infused village of Ulassai with its open-air museum, the Stazione dell'Arte, while the evocative canyon of Sa Brecca de Is Tapparas and the impressive Lequarci Waterfalls—which roar to life during periods of heavy rain—are only a short distance further.
