A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

This sidewalk tribute honors Colorado's great culinary creation.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

This subterranean shrine beneath a bike rental store celebrates the iconic Italian scooter.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A fairy tale castle in modern Rome.

Architectural monsters are devouring this palace's every door and window.

2300-year-old Roman road connecting the empire.

Architectureal fantasy quarter of Rome.

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

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Nearly 300,000 acres of wildlife, natural splendor, and a hidden ghost town have been designated a national monument.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

An oasis of shade and color amidst the bustle of the old city.

The world's largest bamboo labyrinth is a living demonstration of the plant’s immense potential.

Its appearance in "Game of Thrones" may spur on the long-awaited restoration of this medieval shipyard.

This unique temple complex remains off the typical tourist trail.

An Italian hillside ghost town.

A deserted hodgepodge of experimental structures designed by nearby university students.

This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

This natural marble cave is one of only five national monuments in Oregon.