Fort Montalbano is located in a privileged position from which it is possible to dominate the entire Gulf of La Spezia.

Fort Montalbano was probably completed in 1887, after demolishing the remains of the castle and the old parish church of Isola. This fortification was one of the most armed works in the Gulf, it had thirty-eight guns and maintained this function until the end of the Second World War.

After the war, part of the structure was used as an equestrian centre.

It has an irregular shape, which follows the course of the land, and a deep ditch on three sides facing the fronts of Mount S. Croce, Follo and Durasca. To protect it, is present a double caponier on the north-west side. Inside the area there are two squares, a courtyard, a building for the guardhouse, the barracks room, the troop shelters and ammunition stores.

To access the upper courtyard, a tunnel with arches sloping towards the greater slope must be crossed. On the right side of the courtyard you can see the remains of seven binary artillery positions and the relative reserves; the pitches are raised above the level of the square. Each station can be reached via a ramp or two steep and narrow stairways. The pitches are separated by fishbone-shaped brick floors.

The low curtain wall was built with irregular stone ashlars and squared brick openings.

Even if the structure is in a state of almost complete abandonment, its general conditions appear discrete, excluding part of the western nucleus, which was seriously damaged at the end of the Second World War.