After 800 years, Europe's oldest elm tree has met its end.

This golf ball–shaped former desert real estate office now houses a UFO museum.

Two geoglyphs that are truly unique to North America.

A 15-foot-tall statue of the head of the Sopranos family greets passengers at a train station in southeastern Lithuania.

The location where the iconic movie character declared it was time to go home.

Though it's thrived abroad, this forgotten Dunkin' rival has just one store left in the States.

The cell which saved the life of Ludger Sylbaris, "the man who lived through Doomsday."

After being lost for nearly a century, this historic bell finally returned home after its mysterious theft.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

The ruins of a 15th-century castle that has seen its fair share of bitter feuds.

Menacing or in memoriam, the Silent People and their meaning are left to interpretation.

A Roman spa buried deep beneath the City of London.

The commemorative stone column conceals a secret laboratory.

The Great Fire of London and the regulation of one-way streets both started in this alley.

Only a few pieces remain of the structure that carried people and goods across the Thames for some 600 years.

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

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

A roadway designed for a visiting monarch.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

The second-largest natural arch in the Chartreuse Mountains.

Many people don't realize there’s a lot going on in—and below—the world’s tallest triumphal arch.

This clifftop arch is a natural stunner.

This bird-shaped rock formation defies gravity, time, and classification.

Where you can hail your favorite fictional commanders-in-chief.