This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

Dr Barnes' $25 billion private collection of art and arboretum.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

Slyly buy a shake in the Parker Meridien lobby.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Where manatees are the snowbird vacationers in these balmy Florida springs.

Ride the subways of yesteryear.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

Historic funicular railway, believed to be the shortest railroad in the world.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

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

Home to items never before seen by the public.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

A beautiful geyser under environmental threat.

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

A daily replay of the experiment that proved the rotation of the Earth.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

The oldest surviving botanic garden in the United States.