The steep slopes of Italy's volcanic Albano Lake hide a number of archaeological, historical, and natural wonders.  Among these wonders is a nearly inaccessible hermitage: the Romitorio di Sant'Angelo in Lacu.

The trail to the site on the Castelli Romani hiking maps is steep and rocky, making the journey challenging. The site is located above a small canyon on the side of the lake opposite the town of Castel Gandolfo and below the Palazzolo nunnery.

The earliest record of the site is from 1116, from a Papal bull (charter) that mentioned the remote hermitage. It was later restored, in 1282, by Cardinal Savelli, who in turn gave it to the Guglielmini fathers of Montevergine. They occupied the site until the 17th century. In 1773, Cardinal Colonna gave orders to destroy the hermitage—after nearly a century of abandonment, it had become a popular place for highwaymen to hide out.

Nowadays, the ruins of the bell tower, chapel and an unusual structure identified as a meditation chamber that is dug in the local volcanic rock are still visible. There are also a number of deep tunnels and underground storage rooms.

In the recent past the site has often been associated with satanic rituals and on the shore below the hermitage, a woman named Antonietta Longo, was murdered and beheaded in an unresolved murder case from the 1950s.