Cripta del Duomo di Siena (Crypt of Siena Cathedral), Siena (must see)

The Crypt of Siena Cathedral, found beneath the Cathedral of Siena in Italy, is a valuable archaeological and artistic discovery made as recently as 1999. Unlike the original crypt believed to be under the cathedral’s dome, this crypt is a vast space containing remnants dating back to the medieval period, especially from the 12th to the 14th centuries.

Rediscovered during restoration work by the Opera del Duomo, the aim was to uncover the Oratory of Saints Giovannino and Gennaro, located beneath the cathedral's choir. During excavation, a room filled with inert material was found, likely filled in the 14th century due to structural issues halting a cathedral expansion project. This unintentional preservation left the crypt remarkably intact.

Inside, there are thirteenth-century frescoes known for their vibrant colors, preserved due to being sealed shortly after creation. These frescoes depict biblical scenes in two tiers: the upper tier shows Old Testament scenes, while the lower tier features New Testament stories, including scenes of the Passion of Christ. The frescoes offer insight into medieval art and the Sienese school of mural painting. Ongoing studies aim to precisely date and attribute them, which could greatly contribute to medieval art history.

Aside from the frescoes, the crypt contains architectural elements like columns, pillars, and capitals adorned with geometric and vegetal motifs, showcasing pre-Renaissance taste for colorful decoration.

Excavations also revealed the foundations of the cathedral’s oldest apse, shedding light on its construction phases from the 12th to the 14th century, with identifiable features such as stone walls from the 13th century and brick compositions from the 14th century.