Trevi's big museum is the Museo S. Francesco, next to the Gothic church S. Francesco, which is not used for worship any more. It has a few Roman stones, but mostly many Umbrian paintings from the late Middle Ages to the 17th century: the best painting once was part of an altar, and it is by Lo Spagna. There is a very interesting group of "ex‑votos" (paintings to thank God for saving a person from a sickness or an accident) painted by ordinary people, not famous artists, of the 16th‑ century to the 18th‑century.