The world's longest known cave system.

You thought Santa Claus didn't exist, but it turns out you were wrong.

A small store filled with animal skulls and other curiosities.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A charming remnant of 19th-century fishing towns sits on Michigan’s Leelanau Peninsula.

This enchanting forest trail leads to ethereal abodes and a giant bird's nest.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

Eighty million natural history specimens call this gargantuan museum home.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A multiversal transit station located right below a highway interchange.

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

An ivy-covered arch bridge dedicated to Tejano music singer and legend Rosita Fernandez.

Three hundred years of preserved Spanish colonial history in San Antonio.

A gorgeous garden oasis with winding paths, stone bridges, and a troubling history.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

Artist James Turrell's ode to dawn and dusk on the campus of Rice University.

A snapshot of the city's fascinating voodoo culture.

The LSU mascot lived on the college campus in one of the most impressive tiger habitats in the country.