Duomo di Siena (Siena Cathedral), Siena (must see)

Siena Cathedral is one of Italy’s finest Gothic churches and one of the most impressive expressions of the city’s artistic ambition. Dedicated to the Assumption of the Virgin Mary, it was largely completed by 1263 on the site of an earlier church dating from the 9th century. Its design includes a transept, a hexagonal dome, a bell tower, and alternating bands of white and dark marble. These are Siena’s traditional colors, associated with the black and white horses of the city’s legendary founders, Senius and Aschius.

The richly decorated west façade was adorned with sculptures of prophets, philosophers, and biblical figures. Before heading inside, take a look at the three deep, recessed entry arches whose white, pink, and green marble columns sit beneath shimmering golden mosaics. The original sculptures are now preserved in the Cathedral Treasures Museum, while copies occupy the façade.

Inside, the cathedral’s greatest treasure is its extraordinary marble inlay floor. Composed of 56 panels designed by generations of Sienese artists, it depicts biblical scenes, allegories, prophets, and classical figures. The stone-cut artistry literally stretches out beneath your feet. Go past the main entrance thresholds into the primary central aisle to identify the vast network of intricate, narrative pavement panels. Because much of the floor is normally protected, it is fully uncovered only during selected periods.

Another highlight was produced by Italian sculptor Nicola Pisano, who created the magnificent carved pulpit in the north transept. Follow the black-and-white striped nave columns past the main dome pillars to the north transept area. The pulpit is octagonal in shape. Observe how its nine columns support the marble platform, with four of its outer pillars resting on the backs of beautifully sculpted stone lions while the central column stands on a base depicting the Liberal Arts.

The rest of the cathedral's interior is riddled with masterpieces by several of Italy's greatest artists. Donatello’s bronze Saint John the Baptist stands in the chapel dedicated to the saint, while Michelangelo carved four figures for the Piccolomini Altar. Bernini contributed statues of Saint Mary Magdalene and Saint Jerome to the Chapel of the Vow.

Other pieces worth seeing include the choir’s wooden inlays by Fra Giovanni da Verona and a copy of Duccio di Buoninsegna’s great stained-glass window, whose original is displayed in the Cathedral Treasures Museum. Beneath the choir, excavations carried out between 1999 and 2003 revealed a long-hidden 13th century crypt, decorated with frescoes tracking the life of Christ.