Geographical Entry:

The Carso is one of the symbols of Trieste, one of the incomparable beauties of this region. The people of Trieste love this place more than anywhere else, and many people make excursions here on Sundays. The Carso is mainly built of limestone and dolomitic rock. Its formation, which began around 120 million years ago, is due to the sedimentation of microrganisms (animals, vegatables, and molluscs) in a vast sea of which the Mediterranean is just a part. The remains of these microrganisms were deposited on the bottom of the sea and built up layers of white mud which solidified to form stone. The Carso has been modelled into many bizzarre forms because of its exposure to surface water and atmospheric conditions over the last 15-20 million years. Today it is a unique place. The main characteristic of the karstic countryside is that there is no superficial water network. The only visible water course can be found in Val Rosandra. The other short water courses which can be found on the plain, disappear underground and then reappear after having run underground for some time.
There are a lot of caves in this area (some of which have never been explored); the most famous is the Grotta Gigante - it is so big that it could easily contain the basilica of St. Peter's, and it is in the Guinness book of records for this reason.