The Hammer Tower or Tower of Linguella, immediately recognizable at the entrance of the Portoferraio harbor for its octagonal shape, was built in the early 1500s by the Medici, the lords of Portoferraio. It is a supreme example of military architecture designed to defend the harbor.

Over time, it was used as a salt warehouse, later as a tuna fish warehouse and a place for preserving tuna. In the 1700s, the Grand Dukes of Tuscany transformed it into a prison.

After years of decay, in 1977, during restoration work that returned the tower to its original splendor, the remains of an ancient Roman villa were discovered. Built directly on the rocks, the tower has the upper part of its structure significantly more protruding than the lower one, culminating at the top with massive corbels that originally enclosed a terrace used for lookout functions.

In the center of the tower is a small circular structure that is not visible from the outside of the complex. The Hammer Tower, or Tower of Linguella, is located in Portoferraio and is open to visitors for free during the summer as it often hosts art exhibitions.

The Hammer Tower is also known as the Tower of Passannante, after the Lucanian anarchist who on November 17, 1878, in Naples, during the visit of King Umberto I of Savoy, attempted to assassinate the king, grazing him without killing him. As a result of this attempt, he was imprisoned in a cell in the tower and chained to prevent him from moving more than a meter. Sailors passing nearby who heard his gloomy and constant laments began calling it Passannante’s tower.

In 1933, the same Tower of Linguella housed Sandro Pertini, who was imprisoned awaiting trial for insulting a prison guard. This legal procedure followed events that occurred the previous year when Pertini was a political detainee in the Pianosa prison, known for his antifascist activities.