The century-old marble quarrying activity and the consequent valorisation of the area explain the presence of the many important historical monuments in the little town of Stazzema. Against the backdrop of a highly fascinating panorama rise the forms of constructions datable between the 9th and 18th centuries. For scientific reasons, we note in particular the Medici Tower, also known as the Clock Tower, a building which according to the engraving on the architrave of the entrance dates to 1738. The tower owes its second name to the presence of a round clock with a marble quadrant and twelve Roman numerals which conserves the still functioning original clockwork of 1766. Built by horologist Pietro Tommasi, it was restored twice, in 1818 and in 1920, as written on the iron frame. The facade of the tower, beneath the clock quadrant, has a vertical sundial in marble which still conserves its gnomon. Sundials of this type were often used to set the public mechanical clocks.