Welcome to the Grotta Gigante, the Giant Cave!

In the cave, located in the province of Trieste, you will find an exciting reality where tourism, environment and scientific research mix. Here nature shows itself in forms and colors of rare beauty and science hides under the Earth's surface to better study our planet. The cave is one of the most interesting tourist sites in the Friuli Venezia Giulia region and in the province of Trieste, a multicultural city due to its historical and geographical characteristics, which every year attracts numerous tourists and scientists from all over the world. Every year, more than 80,000 visitors enjoy a unique experience in our cave, capable of giving indelible memories.

The Grotta Gigante is owned by the Società Alpina delle Giulie - Trieste Section of the CAI - and owes its name to the imposing size of the cave; it is in fact the tourist cave with the largest room in the world. The large cave, which is the main area of the site, has a volume of 365.00 cubic meters and measures 98.5 meters in height, 167.60 in length and 76.30 in width. The exact dimensions have only been known since 2011 thanks to a measurement carried out with laser-scanner technology by the National Institute of Oceanography and Experimental Geophysics (OGS) located near the Visitors Center of the cave.

The Grotta Gigante was first discovered in the 19th century, when Trieste was under the Austrian domination, and opened to the public in 1908. In fact, in 1840, the Austrians entered the cave for the first time from the current exit, looking for of the Timavo river, a very interesting and mysterious river, known since Roman times for its peculiarity of sinking into the karst soil and flowing underground to the area of the springs near the town of Duino. At that time it was necessary to find sources of water supply for the new aqueduct and the Timavo could have been one of them.

The idea of looking for the Timavo in the Giant Cave was not entirely wrong, in fact, hidden under the surface, there are actually thousands of karst caves in this area. This incredible concentration of caves is possible thanks to the abundance of the two fundamental ingredients necessary for their formation: limestone and water. In fact, water, becoming acidic by reaction with the carbon dioxide in the air, is capable of dissolving the limestone, which makes up the entire plateau of the Trieste Karst. More than 10 million years ago water from rain and rivers began to penetrate the narrow cracks already existing in the rock and, by melting the limestone, it began to widen them. In hundreds of thousands of years, this slow process transformed the narrow cracks into deep wells, long tunnels and majestic caves, which slowly swallowed the surface waterways, giving rise to an intricate underground water network.

The Grotta Gigante, which is a spectacular example of this phenomenon, has long since been abandoned by the waterways, and is now easily accessible. In any case, it is an active cave, in continuous growth and evolution, crossed daily by rainwater, which carries out its work of furnishing the cavity, giving birth to wonderful stalagmites and stalactites.

The water of the rain that falls outside, in fact, penetrates through cracks in the rock until it enters the cave from the ceiling and walls. Crossing the rock, the water melts part of the limestone that composes the rock and transports it to the cave where it releases it. The limestone is thus deposited by the drops in the cave in the form of small crystals partly on the ceiling, around the cracks from which the drops enter, originating stupendous and sharp stalactites, and partly on the ground, where the drops fall, making imposing stalagmites grow, the highest of which measures 12 meters.

In the cave there are also very important scientific instruments such as the geodetic pendulums of the University of Trieste and a seismic station of the National Institute of Oceanography and Experimental Geophysics. In the center of the large cavern there are two plastic pipes that serve as protection for two thin steel cables anchored only in the ceiling. The steel cables support two geodetic pendulums placed in the building at the bottom of the cave. These instruments are used to record the small daily deformations of the earth's crust and also the large earthquakes that occur in every part of the world.

Every year, the cave reserves extraordinary extreme sports shows for its enthusiasts. In June 2013, the world's first base jump in the cave was held, carried out by the Italian David Cusanelli who jumped with his parachute from the highest part of the tourist route. In May 2014, however, the Italian bike trial champion Dario Iacoponi climbed up from the bottom of the large cave, along all the 500 steps that lead outside, with his bicycle, without a saddle and without ever touching the ground with his feet.

In June 2015 it was instead the turn of the performer Marco Milanese who performed breathtaking walks suspended in the void of the large cave on his slackline.

Finally, as every year, the Master's Cronotraversata is held on the last Sunday of November, a timed foot race that takes place along the entire internal tourist route plus a part of the external route.

From April to September, the experiences of visiting the Grotta Gigante are enriched with underground aperitifs based on the typical wines of the Karst. On Saturday evening (6.30 pm), in a unique and certainly suggestive environment, on the terraces inside the Grotta with a view of the large cave, the "underground" aperitif takes place where the part of the protagonist is made by wines such as Terrano, Vitovska or the Malvasia that allow visitors to savor all the flavor of this strip of land rich in minerals and limestone.

In addition, in the spring-summer season there is ample space for families: young and old can indulge themselves and have fun on the 8-meter high tower of the Grotta Gigante where they learn the first sport climbing techniques. You can juggle routes of varying difficulty in complete safety, followed by qualified personnel who will also provide the necessary equipment.

The annual representation of the Befana is dedicated to children, in addition to the wide educational offer reserved for schools, which includes the 8-meter high climbing tower and workshops on the theme of karst, earthquakes or animals. Every 6 January, since 1984, a speleologist, disguised as a Befana, descends from the roof of the cave bringing sweets and gifts to the children at the bottom of the cave, while adults are offered an alcoholic drink with a secret recipe called Gran Pampel. The helpers of the Befana, some Vikings, the Magi, the muccocerves – funny mascots of the Giant Grotta – and the comet join the party.

At the end of the visit to the Grotta Gigante you can explore the Trieste Karst, follow it along its suggestive paths (see CAI n ° 1, 3 and 26) suitable for everyone, amateur or professional walkers, and savor the typical flavors of special products such as wine, oil, honey, cured meats and cheeses.

For more information visit our website www.grottagigante.it, follow us on Facebook, Twitter, Instagram, YouTube, Tripadvisor or download the Grotta Gigante app for free on your mobile phone.