One of the days while there, we decided to go visit the "Cava Grande del Cassibile". We heard it should be very nice, but had no idea what it really is. We assumed some caves which can be visited, but were way far off...
There are some caves with old funeral sites, but those can't be visited easily. The main attraction are some very nice lakes (laghetti) in a very deep valley cut by the Cassibile river. When you get there you see the descent you're about to take (about 600m downwards), and some people kinda think twice if they take the trip or not.
Countless steps and dusty ways take you down the mountain, to a narrow valley full of very nice lakes with clear, cold, mointain water. Some people seem to spend the whole day there, enjoying the view, and the fresh water. Just remember to take some good shoes (not sandals like myself), and a bit of water for the way down (took me about 1.5 hours while going slowly). Halfway there, there is a small heliport (a H made out of rocks placed on the somehow flat surface), and very close nearby there is some kind of aqueduct (you can see me in one of the pictures getting water from there: not a trivial task).
Anyways, it was a very nice day, and I recommend anyone to do it. Just be there in the morning (9-10am) not in the midday like me (around 1pm) when the sun makes it almost unbearable.