This group of caves is one of the most famous in the country. Located in the central region of Marche, the caves were reportedly discovered first in 1948, though most sources state that 1971 is when it began to be explored. They feature a series of linked chambers, one of which is a bizarre shape that feels like an endless tunnel when in fact it is one very long chamber. Today the caves are open to the public for daily visits, and they are estimated to be around 190 million years old.
Up in the northeast, close to Trieste, we find the Giant Cave, the largest cave open to the public in the world. Although several tunnels are linked to the cave, there is actually only one immense chamber. The cave contains some important instruments to measure the movements of the Earth's crust and the sea tides. The overall tour doesn't take more than one hour.
Grotta dei cordari
This cave is interesting because is a combination of a natural cave and the work of mankind. It is closed to the public, but truly fascinating to see even from the outside.
Now, let's go across the sea to Sardinia. This cave has a stalagmite nearly 40 meters tall, almost in the middle of the chamber. The cave also features a long dark hole which is reported to have been used in ancient, pre-Roman times, to sacrifice human lives. This makes it quite a sinister spot to visit.
Remaining on Sardinia we find the Cave of Neptune, the Roman god of the sea. The cave was discovered in the 18th century by a local fisherman, and it has become a hot tourist destination. This grotto is similar to the Blue Grotto in Capri, however this has both a sea entrance and access from the land. Beneath the cave lies a salty lake. Nearby are two other caves, including a green cave that contains prehistoric graffiti.
This cave is actually underwater and it is the largest in the Mediterranean Sea. Not far from Neptune's Grotto, off the coast of Sardinia, the cave is big and features several entrances. Additionally this cave is a virtual aquarium for divers, housing its famous red coral, plants, and fish typical of the Mediterranean.