On the water, the sound from this horn could be heard from up to 10 kilometers away.

The world's longest and deepest train tunnel.

The second-largest giant sequoia in the world.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

A diverse collection of wax, bone, papier-maché and mummified relics.

Once known for its horse-powered knife sharpening, this 200-year-old shop offers an array of blades and hard-to-find culinary tools.

Time has been frozen at this station since the bombing in 1980—or so it was believed.

A large statue of Pope Gregory XIII in Bologna was disguised as Saint Petronius to avoid destruction.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

A striking memorial recalls thousands of Bolognese men and women killed fighting fascists in World War II.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

This building features dozens of faces along its facade, although one is a bit chilling.

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

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

Eat the ultimate iteration of Portugal's most beloved pastry.

Despite the name, this ancient piece of crystal may not have been a lens at all.

A bronze statue of a low three-legged seat commemorates a piece of furniture that started a riot.

Wander among the gravestones in this historic border town.

Sip cherry liqueur at a bar dating back to 1840.

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

Get in line for Lisbon’s most famous sandwich.

Step back in time at this 19th-century kiosk.