Formerly secret, precariously perched boulders.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

When Motown musicians came to Nashville in the 1960s they stayed at this historic record-pressing company because hotels wouldn't host them.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

A sobering account of the vibrant multicultural neighborhood that was destroyed under apartheid.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

A monument to a survivor of harsh pioneer life, frostbite, and primitive surgery.

The skeletons, demons, and corpses serve as a warning of the terrors of Buddhist Hell.

The largest manmade caves in Europe now function as a motorbike club's headquarters.

One of the largest collections of Catalan literature and cultural materials outside of Spain, created by a community of 1960s expats.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

A statue commemorate Tommie Smith and John Carlos's brave protest at the 1968 Olympics, a watershed moment for civil rights.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

The most accurate timepiece in the world.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

Ukraine's oldest operating pharmacy now offers guests a fascinating walk through apothecary history.

A bronze statue on a downtown corner honors Minneapolis's favorite career gal.

An abandoned jewel of a ballroom on the top floor of Australia’s busiest rail station echoes with the sounds of a bygone era.

A headstone tells the sad story of a lost little boy and his pet dog.

An ancient necropolis of magnificent tombs.

The "world's smallest volcano" has been used to store meals and dispose of dead bodies.

The early American colonists were such ferocious drinkers the law actually required every town to have a tavern.