Forever linked to the veneration of Saint Catherine of Siena is the great Basilica of San Domenico. It was built at the same time as the domenican convent, between 1225 and 1265, and is fully gothic in its formation. The gothic style manifests itself here in the guant and severe architecture, constructed entirely in brick.
Inside, in the Chapel of the vaults, is the fresco by Andrea Vanni, painted in 1667. It is the only remaining work depicting Saint Catherine that can be considered to be a true portrait of the saint.
The Chapel of Saint Catherine of Siena, moreover, preserves the remains of the head of the saint, kept on the wonderful marble altar, the work of the sculptor Giovanni di Stefano (1469). The chapel is entirely covered in oils and wall paintings of very high merit, amongst which, on the sides of the altar, are two famous masterpieces by Sodoma, from 1526, the Rapture of Saint Catherine and the Eucharistic Vision. On the other side of the chapel, there is one of the few pictorial works by the Sienese Francesco di Giorgio Martini, who was better known for his architecture: the Adoration of the Shepherds (1475-80). And in the fifth chapel, there are another two masterpieces of Sienese art on tavolas. The first is the Madonna on the throne with Son and Angels, Saints Gregorio, Giacomo, Girolamo and Sebastiano, which is believed to be one of the best works of Benuto di Giovanni (1483). The other, Saint Barbara on the throne between Saint Maddalena and Catherine of Alessandria is perhaps the greatest masterpiece by Matteo di Giovanni (1479), today returned to splendour and to its original brightness thanks to a recent restoration.
On the left walls of the church there is another series of notable works, amongst which is a large tavola by Sodoma, depicting the Eternal Father and Saints Vincenzo, Ludovico, Sebastiano and Catherine of Siena.