An acoustic anomaly with a mysterious cause sits in the heart of Tulsa.

A controversial memorial at the place where Captain Cook met his violent end.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

Elaborate tile work in this railway station tells the story of Portugal.

Gustave Eiffel's masterpiece until the Eiffel Tower was built.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

The first documented commercial gold find in the United States.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

Sip cherry liqueur at a bar dating back to 1840.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

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

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A colossal statue of a woman hugging a modern building.

Macabre astrological automaton clock dating to the late 1400s.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Whether or not you take the 72-ounce steak challenge, there’s plenty of history, fun and Texas-style food at this legendary stop along Route 66.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

Browse through a century of this principality's first popular export.

This skeleton-filled altar piece served as a backdrop to one of the most iconic scenes in "The Sound of Music."