A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

This mysterious ancient arch is hidden in the forest of Simbruini Mountains Regional Park.

The ruins of this once gorgeous medieval church are still standing, despite the region's constant flooding.

This medieval city gate is now a blend of the past and the modern world.

Knights Templar are visible inside this stunning Cistercian abbey.

The hilltop town of Segni was once home to an ancient Roman colony and garrison.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

This medieval hilltop village was abandoned at the end of the 19th century, after existing for more than 500 years.

The meaning behind this triumphal Roman arch was a mystery until the early 20th century.

A monk spent 14 years carving steps through tuff to make this religious site more accessible to pilgrims.

A massive bridge forms part of an aqueduct that was deemed an architectural wonder of its time.

The collar worn by a fourth-century saint resides in this church, and is still used for blessings to this day.

Magnificent frescoes decorate the interior of this Romanesque church, which also showcases an unusual phenomenon during winter solstice.

Was this cave created by Hercules's wrath, the devil, or volcanic activity?

All that is left of this medieval castle is two towers, both of which now display a visible tilt.

This medieval settlement was abandoned after a series of landslides. What remained was largely destroyed during a mock battle for a WWII film reel.

The pristine waters crossing this forest form a hidden waterfall among the dense vegetation.

The remains of this medieval Roman road and lookout towers dot the rugged coastline of southern Lazio.

Hidden in a high mountain cave, this hermitage dates back to the ninth century.

One of the oldest libraries in the world is still operating and contains the oldest existing document in the Italian language.

A Roman temple perched over an Italian town, forgotten several times over.

An omelette made with over 1,000 eggs may have been prepared when Holy Roman Emperor Charles V visited this monastery.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

This massive rock balanced for thousands of years being tossed here during a volcanic eruption.