St. Mark's Clocktower, also known as the Moors' Clocktower, is a medieval clock tower located in St. Mark's Square in Venice, Italy. The tower was built between 1496 and 1499 by the architect Mauro Codussi, and its main feature is the astronomical clock that adorns its facade. The clock is a beautiful example of Renaissance engineering, with its bronze figures striking the hours and an intricate mechanism that indicates the position of the sun and the phases of the moon.

The tower's name is derived from the two bronze figures, known as the "Moors," who strike the hours with their hammers. These figures are thought to have been modeled on real Moors, who were once a common sight in Venice due to the city's historic trading links with the Middle East.

The clock tower is also adorned with other decorative features, including a pair of winged lions, the symbol of St. Mark, and a large bell that was used to summon the city's citizens in times of emergency. The bell was also used to signal the start of public executions, which were carried out on the square below the tower until the 18th century.

Today, visitors can climb to the top of the tower to enjoy panoramic views of Venice and to see the clock mechanism up close. The tower is a popular tourist attraction and an important landmark in Venice, serving as a symbol of the city's rich history and cultural heritage.