LE GROTTE DI FRASASSI The Frasassi caves in Le Marche Italy were formed thanks to the river that runs above them. The caves are truly enormous, wonderfully cool year-round at Celsius, and they have a wide variety of stalactites and stalagmites.
Cuevas del Drach are caves located near Porto Cristo in Mallorca, Spain. It contains one of the largest underground lakes in the world. Once you reach the underground lake (Lake Martel), you can see musicians on the boat playing classical music.