The patron saint of Casacalenda is Saint Onuphrius, celebrated on 12 June: the patronal feast includes Mass in the church of Santa Maria Maggiore and a procession through the town's streets. The convent dedicated to him, from the 15th century, was built in 1407 by Father Giovanni da Stroncone and stands outside the town centre: it has a spacious quadrangular cloister with a portico, on whose walls traces of Renaissance frescoes are still visible, a refectory, 25 cells on the upper floor and a secondary 19th-century wing; the church, divided into two naves, preserves other works of art inside.
The most important house that ruled Casacalenda in history was that of the Caracciolo and Capua families: in the 14th century the fief, then called «Casalchilenda», passed to Riccardo Caracciolo through his wife Mattea da Casalchilenda, in 1324. The Palazzo Ducale, which stands on the site of the old castle, has a late-16th-century appearance with an irregular square plan, bastions at the base and a loggia of windows on part of the facade.
