Tower of Santa Maria, Defensive tower in Pisa, Italy.

The Tower of Santa Maria is a square-plan tower closing the north-west side of Pisa's old city walls near Piazza del Duomo. Built from large blocks of Livorno sandstone, it has a slightly tapering profile; the upper part, including the crenellated crown, dates to 19th-century raising works.

The tower was built between 1155 and 1161, right after Pisa's city walls, using large blocks of Livorno sandstone. It and the nearby Torre del Leone guarded the Porta del Leone and the bridge over the Auser, a possible entry route for enemy armies. The old top was razed in 1499 after the Florentine conquest; the upper part and battlements date from 19th-century raising works.

This tower reflects how medieval Pisa organized its defenses through stone structures and military positions. Visitors walking along the walls can see how these towers once formed a connected network protecting the entire city.

The tower sits along the historic city walls and can be visited as part of a walk through Pisa's fortifications. The best way to experience it is on foot, following the wall sections that wind through different parts of the old city.

This tower has kept its original place as part of the unbroken wall system that once wrapped around the entire city. Today visitors can still walk sections of this continuous fortification network and see how it connected different parts of Pisa.