A Hawaiian stairway to heaven—that you can't climb.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

Race through the maze, get your name on the sign.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

Less a museum than a bizarre fantasy world created by artists and engineers.

One of the world’s largest living advertisements is made out of pine trees.

Buffalo's abandoned concrete grain elevators are getting a second life.

Museum dedicated to the struggles of the disabled.

A natural gas leak provides a flickering flame beneath a waterfall.

An eerie diorama that captures the majestic nature of a few prehistoric-looking beasts.

Creating this diorama spurred naturalist Carl Akeley to begin advocating to protect the apes.

This poignant display is now a memorial to these regionally extinct species.

This taxidermy scene brings the struggle for survival in the Indian jungle to a quiet corner of a Manhattan museum.

This magnificent herd of stampeding elephants has been frozen in time for over a century.

This subterranean oyster house has been the pearl of Grand Central Station since 1913.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

Visit the monolithic tomb of America's most famous general.

Lie in a hammock where George Washington stood.

Ride the subways of yesteryear.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

A semi-scholarly approach to sex.