The Church of San Marco in Grotte di Castro was built between the end of the 19th and the beginning of the 20th century based on a design by architect Enrico Buratti. The building has a single nave and houses several works of art of considerable value.

Among the most significant paintings is the Madonna with Child and Saint Anne between Saint Lucy and Saint Blaise, donated to the church in 1729 by the weavers’ guild. Also of particular interest is the 17th-century canvas depicting the Virgin in Glory between Saint Louis, Saint Joseph, Saint Vincent Ferrer and Saint Mary Magdalene de’ Pazzi. In addition to these are The Death of St. Joseph, a work by Matteo Pacelli from the first quarter of the 18th century, and a painting of St. Anthony the Abbot dating back to the 16th century.

The church also houses two 17th-century statues: one of St. Anthony of Padua and one of the Immaculate Madonna, evidence of the popular devotion that has accompanied the history of the local community.