It lies in an area of great archaeological interest, a short distance from the cliff necropolises of Grotta Porcina, Valle Cappellana, Blera and Barbarano Romano, in a breathtakingly beautiful countryside immersed in ancestral silence. The name San Giovanni was given to it in 1550 by Giovanni Anguillara of Ceri, who promoted the arrival here of about twenty farmers from several parts of Italy to populate the area and organise the cultivation of the land.

The parish church of San Giovanni Battista (patron saint of the town together with Alban and Benedicta) was built in the early 1700s with the active participation of the inhabitants, over the ruins of a previous church. The interior, with one nave in the late Baroque style, houses an altarpiece by a local artist of the nineteenth century (Francesco Guerrini), depicting the Birth of St. John the Baptist, and a painting of the town, executed in around 1865. The town was the birthplace of Simone Medichini (1831-1916), an expert in natural sciences and a member of the Accademia dei Nuovi Lincei, and Father Mauro dell' Immacolata, whose name is linked with the cause of the beatification of Maria Goretti, as her postulator and biographer. Near the town, at Valle Cappellana, is a tumulus of magnificent proportions (seventh-sixth century BC) on which there open two tombs relating to various local agricultural settlements. The main one consists of two chambers, separated by a pair of Doric columns sculpted in the tuff, with three funeral beds. In one of the two cells of the second tomb, simpler than the first, there is a seat dug out of the rock with the relative footstool. Outside the tumulus, a peperino statue was found depicting a reclining lion, now housed in the small museum in Barbarano Romano. At the end of the restoration works, treasures were discovered in the funeral complex consisting of a series of aryballoi of the archaic Corinthian age, various gold fibulae, bucchero kylikes and goblets.