Torre del Diavolo, Medieval tower house in San Gimignano, Italy.

Torre del Diavolo is a medieval tower house standing on Piazza della Cisterna, the main square of San Gimignano in Tuscany. It rises noticeably above the surrounding buildings, with a plain stone facade and narrow windows typical of the residential towers that once filled this town.

The tower belonged to the Palazzo dei Paltoncini, later Picchena, Lupi and finally Cortesi, which occupied the north side of Piazza della Cisterna. Tower and palace formed a single connected unit typical of the local nobility and upper bourgeoisie in the Middle Ages. Both were modified over time, and the changes are still legible on the tower's east side, where large internal arches opening into the neighbouring house were later walled up. The brick altana on top probably dates to the Cortesi alterations of the 16th century.

The name comes from a legend: a rich merchant returned from a trading trip and found his tower taller than before, which he could only explain as the work of dark forces. The tower belonged to the Paltoncini, later Picchena, Lupi and Cortesi palaces, and its slightly sinister protruding supports likely fed the tale.

The tower is best seen from Piazza della Cisterna, where you can step back and take in the full height of the building from the outside. Going early in the morning gives you more space and a quieter view of the square.

The tower's name comes from a legend, not a documented event: a merchant returned from a trading trip and found his tower taller than before, which he blamed on the devil. The sinister look of the protruding stone supports at the top likely fed the story. The tower also appears in the video game Assassin's Creed II, where players can climb it.