In the area where today San Nicolò stands, there was already a church named after St. Nicholas from Bari. A 1089 consecration of a church by this name is also attested. Such building was granted in 1263 by bishop Accoramboni to the Augustinian Friars, who also obtained the next church of St. Maximus.
In 1304 the friars started erecting a new big temple, with annexed convent, in the area of the two churches, that would become a cultural centre radiating all over Italy. The church has a simple, rectangular plant that ends in a very high, polygonal apse; under a pitched roof, the façade is embellished by a big ogival, carved portal, in moderate Gothic style. A 1412 fresco portraying Madonna with Child between St. Augustine and St. Nicholas by Maestro della Dormitio from Terni is visible in the lunette.
The inside has almost totally lost its decorations, including numerous chapels built between the 14th and the 17th centuries; it now features a wide, rectangular hall and a trussed roof ending in a tribune on which a majestic umbrella vault with mullioned windows is set.

AA.VV., L’Umbria, Manuali per il Territorio, Spoleto, Roma 1978