Enjoy a slice while browsing the world's largest collection of pizza memorabilia.

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

The first American department store, and home to the largest operating musical instrument in the world.

The last Viking king of Denmark is buried inside the crypt of this cathedral.

The oldest active church in Pennsylvania is also the second oldest Swedish Church in the United States.

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

This elaborate towering structure was once famed for its revolutionary height.

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.

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

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

The oldest surviving botanic garden in the United States.

A renowned Civil War veteran, this Bald eagle now presides over the Wisconsin State Assembly.

The beloved, war-tested mascot of a Union regiment graces their battlefield monument.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

After the musical legend's death, his memorial was mysteriously graffitied in gold.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

The location of the world's first telescope demonstration.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

A tiny, unmarked beer and whiskey bar above an Ethiopian restaurant in West Philly fails to conceal live bluegrass.

Elevated freight railway turned wildly successful urban park.

Before he was America’s most famous preservationist, John Muir was an ingenious mechanical inventor.

This historical Netherlands fortress still bears the marks of its single siege.