Grotta gigante

© Corrado Pravisano/Shutterstock

Grotta Gigante

Friuli Venezia Giulia

The Carso's big-ticket attraction is this enormous underground cavern near the town of Opicina. At 120m high, 280m long and 65m wide, it's one of the largest caves in the world, filled with stalactites and stalagmites. Knowledgeable guides point out the cave's features, which include two huge pendulums that monitor the movement of the earth's crust. Upstairs there's a small Speleological Museum, which includes fossils and objects found in the cave, including the skeleton of a now-extinct karst bear.

To reach the cave from Trieste take bus 42, or tram 2 and bus 42 in the other direction.

Lonely Planet's must-see attractions

Nearby Friuli Venezia Giulia attractions

1. Casa Carsica

1.64 MILES

This house museum in Rupingrande re-creates life in the pre-modern Slovenian-speaking Carso. It also organises the plateau's most important folk festival,…

2. Faro della Vittoria

2.38 MILES

Trieste’s elegant lighthouse, with its 68m-high, fluted tower and copper dome sporting a soaring Winged Victory, is perched on the Gretta Hill and worth a…

3. BioMa

2.56 MILES

The Immersive Museum of Miramare Marine Protected Area, located at the former Miramare stables, showcases the marine biodiversity of the Gulf of Trieste…

4. Castello di Miramare

2.57 MILES

Sitting on a rocky outcrop 7km from Trieste, Castello di Miramare is the city's elegiac bookend, the fanciful neo-Gothic home of the hapless Archduke…

5. Civico Museo Teatrale Carlo Schmidl

3.93 MILES

Trieste's long-standing cultural cred is documented at this museum, housed inside the grand Palazzo Gopcevich, with a collection that traces the city's…

6. Borgo Teresiano

3.94 MILES

Much of the graceful city-centre area north of Corso Italia dates to the 18th-century reign of Empress Maria Theresa, including the photogenic Canal…

7. Synagogue

3.96 MILES

This imposing and richly decorated neoclassical synagogue, built in 1912, is testament to Trieste's once significant Jewish community. Heavily damaged…

8. Statue of James Joyce

3.98 MILES

James Joyce's presence in the city is palpable, but if you're not feeling it, this bronze statue will help. He's often surrounded by Irish visitors and…