Isola Santa is a very old, Medieval village, built around a hospital for travelers and pilgrims on a cliff overlooking the river Turrite Secca. Before 1950, the borgo was sitting on top of an outcropping, but the construction of a dam for hydroelectric power and the resulting man made lake put the buildings at the level of the lake. The hydroelectric project forced the inhabitants to leave their homes. In recent years, a restoration project brought life again on the shores of the lake but Isola Santa has the feel of a Ghost Town, with most of the houses laying empty and only a few trout fishermen and trekkers passing through. The surrounding forest is full of chestnut trees and porcini mushrooms.
Although tiny, the place is magical and very photogenic. The Church of San Jacopo, built in 1260 boasts a wonderful bell tower, and there is even a restaurant to indulge in a meal or two--Casa del Pescatore. Hikers and climbers can head off toward the peaks of the Apuan Alps from the village. And although it might look like snow in summer, those mountains are made of marble, as is nearby Carrara where Michelangelo saw his David in a huge chunk of the white stone.
This is also Karst country--making this an area rich with caves. Worth a visit is the impressive Grotta del Vento (on Garfagnana), and the 1 mile long Antro del Corchia, which is the widest cave of whole Europe (on Versilia). This cave system contains over 30 miles of chambers and tunnels in its system. The Karst geology in the area also created streams that disappear into underground caves, only to reappear elsewhere as springs. Just before reaching Isola Santa is La Pollaccia, one of the more important natural springs in Italy.
If you are into hardcore mountain climbing, this is really the area for you. The mountains are rugged, they are world class with many peaks requiring a high level of climbing skills and equipment. If you're up to it, think about climbing Monte Forato just to the south of Isola Santa. It's got a prize at the top--a huge, natural land bridge forming a hole right through part of the ridge.