One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

In Chicago, a pizza-enthusiast has opened a museum dedicated to the history of pizza.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

This modest post office sits on the site of H.H. Holmes' famous murder castle.

This historic hotel invented the chocolate brownie.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

A beautiful geyser under environmental threat.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

An indoor miniature village and labor of love for Laurence Geiringer, a model railroad enthusiast.

The only thing better than tubing down New Jersey's scenic Delaware River is doing so while eating a hot dog from a giant floating stand.

A unique sculpture park that specializes in the huge and bizarre.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

Delicate Wurlitzers, creepy clowns, and The Noid all share space in this insane explosion of kitsch history.

The first partially complete dinosaur skeleton was discovered here, forever changing the world's view of the ruling reptiles.

The oldest surviving botanic garden in the United States.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

Yo, Adrian!

World's first "penitentiary," meant to be humane, drove men insane.

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

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

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

An Irish Memorial commemorating those who perished due to potato blight.