Located 400 meters from the center of the village with the same name (Borgo Grotta Gigante, fraction of Sgonico municipality) it was explored for the first time in 1840 by Antonio Federico Lindner, in the attempt to discover the underground course of Timavo river. But really its initial part was already used by man since prehistory age till Roman age, as proved by the remains found at the bottom and evidently fallen from the top.
Some year after, the fireman Giovanni Sigon risked there his life for the breach of the scales. Then there is no news of the Giant Cave until April 20th 1890, when the second entrance was found (currently inside the Speleological Museum) from which the speleologists carried out one new exploration and the first relief. Then the visits were continued until 1904, year in which the Touristi Triestini Club - one of the three big active societies of Trieste in alpine and speleological field - determined to render touristic the cavity, buying it and beginning the jobs for to equip it, using for such aim a third entrance (the current one) founded meanwhile.
In 1908, after four years of work, the cavity, illuminated by 4000 candles, was inaugurated at the presence of authority and big crowd, while on the bottom a band cheered those present playing excerpts from Siegfried.
After the first world war the cave passed to Julian Alpine Society (Società Alpina delle Giulie), current its owner, that in 1957 realized the first electrical lighting system, completely rebuild some year after.
A series of Karst hard stone steps lead down, then a short descendent gallery, until a door, beyond that you can reach a first belvedere from which is starting a great steps. This way (down till the bottom and back up) is part of a running competition that is played once a year in this village.
We don't suggest you the visit at race step. In fact the environment with its stalactites and stalagmites are beautiful and the main cavern, high 107 meters, long 280 and wide 65, is so immense that it could contain the Saint Peter's Basilica. This cavern has been inserted in the Record Guiness Book since 1995 as the biggest tourist cavern in the world.
The two wide galleries that carry to the cavern are the last rests of a large underground Karst system that thousands years ago swallowed two torrents of remarkable capacity. The "Altar Room" (Sala dell'Altare), an immense cavern situated at the extremity of that main one, constitutes a resting point during the tour.
Instead the "High" entrance lead to a gallery that ends up nearly the top of the great cavern (this entrance was used by Lindner).
Characteristic of this cavity is the stalagmites that have the shape of palms, the biggest of them is the Ruggero column.
Since 1996 the tour continues along a new path - the "Carlo Finocchiaro" path - than, touched the Altar Room, goes up along a ledge. At its end some flight of stairs carry to a new splendid panoramic point. Therefore the tour goes on following an artificial gallery that carries to another lookout near the geodetic pendulums (highest in the world): under the balustrade there is a hundred meters jump. A short time ago the tourist way it has been ulteriorly enriched with an original skeleton of Ursus Spelaeus, the biggest mammalian that was living the caves. Another pair of steps and you are outside, a gorge, that it is how remains of a part of cave whose ceiling has been abraded some millenium ago, in which a peculiar vegetation of the Karst abyss entrance is taking root.
