The church of San Domenico stands on the eastern side of Piazza Leopardi and is worth a quick visit principally for one painting: a fresco of Saint Vincent Ferrer in Glory by Lorenzo Lotto, painted in 1513 and one of the earliest works of the Venetian master's long residence in the Marche. The fresco is in a side chapel on the left; the rest of the church interior, redone in the baroque period, is pleasant but unremarkable.
Look up at the Gothic side door on Via Falleroni — a fine example of the ogival arched portals of the Marche. The church is normally open in the mornings and for evening Mass.