Official Information
Official site: https://www.grottagigante.it/
Address: Borgo Grotta Gigante 42/A, 34010 Sgonico (TS), Italy
Map: View on Google Maps
Opening Hours
Access is by guided tours only, with fixed departure times on most days of the year, typically late morning through the afternoon. Exact schedules change seasonally; check the official website for current times. Visitor numbers are limited, so advance booking (online or by phone) is highly recommended, especially on weekends and in high season.
Grotta Gigante, set above Trieste in the rugged karst hills, hosts one of the largest show-cave chambers in the world, once holding a Guinness World Record for the size of its main cavern. A tour begins at the visitor center before a descent via a dramatic staircase into the immense underground hall, adorned with impressive stalactites, stalagmites, and flowstone. The chamber towers more than 100 meters high, creating a striking sense of scale. Guided tours (usually about an hour) lead visitors on a set route down and back up, totaling around 500 stairs each way, with regular stops for explanations on local geology, cave formation, and scientific instruments used to monitor earth movements. Lighting is atmospheric but keeps the focus on the natural formations, and personal photography (no flash) is allowed. The cave is cool year-round, so bring a light jacket and sturdy shoes even in summer. Because of the extensive stairs, tours aren’t suitable for anyone with severe mobility issues or heart/lung conditions. Most tours are conducted in Italian, but multilingual explanations may be provided depending on the group. Grotta Gigante is a popular day trip from Trieste (20–30 minutes by car or bus), making for a memorable natural contrast to the city’s Habsburg architecture and seaside atmosphere.