Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Go inside to really appreciate this 500-year-old technological masterpiece.

The world's oldest surviving anatomical theater, where "the dead are pleased to help the living."

In medieval times this small stone seat was used as a bizarre way to punish insolvent debtors.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Home to the deepest rift anywhere on Earth.

Water flowed out of the town's unusual tree stump fountain in the 1930s, and the well still runs today.

An earthwork sculpture built by Robert Smithson in the Great Salt Lake only reemerges during drought.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Erosion and various mineral deposits give this striking canyon its distinct color and soft appearance.

A tunnel with windows, so you don't miss out on the impressive views.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

The fifth-longest natural arch in the world, and the longest outside China.

Despite its name, this route in southern Utah offers a heavenly day trip.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

The ruins of an important pilgrimage destination for worshippers of a Maya fertility goddess.

A brutalist gem towering over the heart of Milan.

Legend says the only thing buried within this magnificent tomb was a dog.

The Adriatic's most famous wind can be reliably experienced in the city's Marina.

This fountain is dedicated to the workers who perished constructing the Fréjus Rail Tunnel.