A Nesting Doll of Churches.

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

Inside this building is another country within Rome, a sovereign entity without a physical territory.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A forgotten "city of water" underneath the famous Trevi district.

An alchemist's "magic door" stands in the middle of a Roman park.

Architectural monsters are devouring this palace's every door and window.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A magnificent Neogothic tomb hides within this Italian fairytale-like forest.

Nine caves filled with recently-discovered archaeological finds under the houses and the streets of the most ancient district of an old town.

This 16th-century monastery has been turned into a surrealist architecture compound.

Nestled in the hills of Tuscany are gorgeous, multicolored hot springs.

A unique Tuscan hideaway acts as an art mecca as well as a hotel.

This lesser-known leaning tower is all that remains of the medieval castle of Vernazzano.

This memorial to a horrific ship collision sits over a mass grave holding dozens of the victims.

This former prison now houses a lovely library devoted to Quebec's oft-maligned English-speaking history.

A 400-square foot model of historic Quebec is the playing field for a state of the art light and sound show.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

Artistic cabins actually grow deep in the Canadian wilderness.

A former chicken restaurant that doubled as a speakeasy is now a quirky home full of wonderfully strange traditions.