Torre Rognosa, Medieval tower in San Gimignano, Italy.

Torre Rognosa is a square-based stone tower rising almost 52 metres from the old Palazzo del Podestà on Piazza del Duomo in San Gimignano, making it the town's second-tallest tower after the Torre Grossa. Its shaft of rough light-brown blocks has few openings, and the top carries a projecting bell chamber with a wide arched opening and a tiled pyramidal cap.

The tower was built around 1200 and originally belonged to the Gregori family before later passing to the Oti family. It subsequently became a municipal prison, marking an important shift in its role within the city's life.

The name "Rognosa" comes from the tower's use as a prison after the podestà moved out: it was visited by those who had "rogne", troubles. The top floor holds a laical bell chamber, later the bell that struck the hours, under a small pyramid of red tiles.

The tower is easy to spot from Piazza del Duomo and can be viewed from the outside without needing special access. The best viewing angle comes from different spots around the main square, where you can also see other medieval buildings nearby.

A law from 1255 banned the building of towers taller than this one, showing its importance in the city's power structure at that time. This rule reflected how San Gimignano controlled its skyline and balanced power among families.