An optical illusion found amid a logged redwood forest.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

An unassuming secret door once led to a legendary watering hole.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

The Pope’s secret escape route.

Breathtaking and huge 430 year old maps of Italy.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

Site of the largest impact event to occur over land in Earth's recorded history.

Known for the tunnel that leads visitors to the water.

Considered the most remote point in the entire world.

These passages carved from the Antarctic ice hold strange shrines to the harsh southernmost climes.

Marked by the hand of the explorer Henry Morton Stanley.

This ancient burial site is believed to be one of the first earthquake-protected structures in the world.

The palace of the King of Kings, burned by Alexander the Great.

The encased skull that is widely believed to belong to St. John the Baptist.

Science fiction's grandfather has a fittingly marvelous tomb.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

The handiwork of a underdog clockmaker who solved an impossible problem for an Empire, and forever revolutionized seafaring.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

A trio of red, white, and blue stones embedded in the streets of Leiden are markers of medieval territory and law.