Traces of Castelfranco di Sotto’s past can be seen in the historic buildings that survive to this day. The collegiate church of San Pietro and San Paolo, the town's main church, is home to two wooden statues of the Annunciation by Nino Pisano, along with a fervently venerated fifteenth-century crucifix. The seventeenth-century church and convent of San Matteo is also interesting, not least for a depiction of the Madonna in Glory with St Matthew, St Anthony of Padua and Cardinal Carlo Borromeo. Also worth visiting is the church of Santa Maria Maddalena, which everyone knows simply as La Badia.
Evidence of an even older past survives too, of which the highlights are two archeological exhibitions, one in the centre of Castelfranco and another in the hamlet of Orentano. The former has a range of finds dating from prehistory to the Middle Ages; the exhibition in Orentano, meanwhile, is full of woodwork, stonework and metalwork, pottery and coins, all of which tell us something about the history of the area. Its two main showpieces are the remains of a Roman bridge and a medieval canoe, which was used to cross the neighbouring lake of Bientina.
The territory is also known for the beauty of its outdoors, as it makes up part of the Montefalcone Nature Reserve. This is most important natural park in the Cerbaie hills, which rise above the marshland between Bientina and Fucecchio.