In the ancient beech forests of Monte Fogliano, a 16th-century holy man, Fra Girolamo Gabrielli from Siena instructed his city's craftsmen to carve a rock-dwelling from an enormous volcanic boulder.

Gabrielli was seeking a place to pray and meditate. He resided in the woods for a few years, from 1525 onwards, before the descent of Landsknecht mercenaries from the Germanic regions of Europe onto Rome. This led to the destruction of the city and interrupted his peaceful, solitary life. According to local lore, the Landksnecht abused him and destroyed his dwelling. Gabrielli decided it was safer to return to Siena and he subsequently donated all of his belongings to the poor.

Today, several trails through the forest lead to this stunning and mysterious site. Devotees from Vetralla maintain the site and hold a yearly mass at this location. The area contains a simple chapel dug into the rock. Several niches and windows reveal an elaborate design, along with an open altar and stone bench for gatherings.

Just below the site is a convent known as the Convento dei Padri Passionisti di Sant'Angelo. It dates back to the Lombard age around the 6th-century CE, however, current aspects date back to the 18th-century.

Above the site is a 30-minute trail that leads to the peak of Monte Fogliano, from which visitors can observe Vico Lake. Monte Fogliano is a Site of Community Importance because of its ancient beech forests. It is particularly stunning in the autumn.