Centuries of warfare, tragedy, executions, and poetry come together in this 13th-century fortress.

Tiny castle in the middle of the Rhine made you pay to pass.

Legendary site where an evil bishop was devoured by rodents.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

A tower-like theater in the Swiss Alps built to withstand the high winds and avalanches of the mountain pass.

The remains of St. Lucius of Chur were said to be kept in this crypt for several centuries.

The great Danube river starts here.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

A unique form of erosion created an uncanny landscape of boulders perched atop slender columns of clay.

A family accused of witchcraft once called this medieval tower home.

This work of engineering is imbued with elegance and ingeniousness.

Gladiators once walked this ancient, subterranean passage.

This former mill comes to life during the Christmas season.

What appears to be an ancient Roman temple is actually a Catholic church.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

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

Nobles would stage mock naval battles on this large lake at the Royal Palace of Caserta.

This Roman amphitheatre was also the location of the first gladiator school.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

The sacristy of this church contains remains and relics of members of the Aragonese royal family.

Richard Luke Concanen never set foot on American soil.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.