Under the right conditions, rocks will move across this dry lakebed, leaving trails behind them.

This ordinary-looking mailbox has a rather explosive history.

The U.K.'s first underground railway line is now a lively thoroughfare for runners and cyclists.

Small sculpted heads of prominent phrenologists mark the outside of their former headquarters.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

The most loyal of little dogs, or a Victorian era publicity stunt?

This monument is dedicated to a young boy who survived a disaster that forced Edinburgh to reevaluate its building codes.

This stately bank building hides a spectacular star-studded ceiling.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The collection of a paranormal investigator who traveled the country collecting haunted items and stories.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

A 18th century graveyard and its astonishing cortege of macabre iconography.

360° views of the city plus five floors of optical illusions and hands-on science.

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

An American ghost town hides along a side street in Scotland's capital.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.

A hidden "place of interment for gentlemen."

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

Residents of Fremont in Seattle have considered it the center of the universe since the 1970s.

This semi-secret garden in south Seattle emulates a traditional Japanese garden using the plants of the Pacific Northwest.

Dine on dumplings at the oldest dim sum restaurant in New York.

Visit the site of a subway powered by nothing more than air--and lots of it.

This town is home to the world’s largest arch constructed entirely of elk antlers.