On the outside, the ashlar facade and, on the tympanum, the coat of arms of the Teatini stand out; inside, on the wooden ceiling, are painted scenes of life of San Nicola, made by Carlo Rosa.
The church of S. Gaetano was built in the first 600 by will of the Teatini, who intend to have their own place of worship. The building is built on the remains of the City Palace, thanks to the contribution of Governor Cesare della Marra. It was consecrated in 1730.