Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This shop for all your super spy needs hides an educational secret.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

The experimental test tracks of a retro-futuristic monorail still stand in the French countryside.

César Baldaccini's iconic sculpture of a 40-foot thumb stands tall in La Défense.

This miniature Paris, built out of trash, is one man's two decade labor of love.

The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

France's Lilliputian park displays over 100 of the country's monuments for visitor perusal.

French Time Capsule-19th Century home revealed to the public.

A curious collection of locks and keys.

Series of underground houses inhabited continuously for centuries.

Artist and musician Will Menter creates musical sculptures.

Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

Green labyrinth formed by a karstic maze hidden in a preserved oak forest.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

Since ancient times these picturesque springs have been providing bathers with healing waters.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

The world's largest reflecting pool is just two centimeters deep.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

One of the world's most complex timepieces.