A layered tribute to the work of mosaicist Isaiah Zagar.

One of the oldest of its kind.

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

Yo, Adrian!

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

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

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

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

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

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

Alexander Hamilton’s creation caused quite a bit of controversy.

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

This hidden gem of a garden has one of the only surviving Victorian ferneries in America.

One of the world's largest model railroads is a mind-boggling achievement.

Frank Lloyd Wright built this suburban synagogue late in life, but it stands among his most iconic masterpieces.

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

A bronze monument to the infamous radio broadcast in the real New Jersey town where the fictional Martians crash-landed.

The final resting place of many of New Jersey's most famous residents, including U.S. history's most in-vogue antagonist, Aaron Burr.

The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

Nassau Hall has served as army barracks, a museum, and played a key role in the American Revolution.

These 20-foot sculptures will help guide you from the local train station to the local sculpture garden.

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

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

The world's longest known cave system.