Once America's tallest structure, now a Baltimore landmark.

Nine of the very few concrete ships ever made in the U.S. are beautifully decaying off a Virginia pier.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

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

A layered tribute to the work of mosaicist Isaiah Zagar.

Mural made of 100,000 pieces of hand blown glass, and one of the largest glass murals in the US.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

A pride of the state, this working museum crafts pottery mosaics in the style of Pennsylvania's earliest European settlers.

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

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

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

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

Yo, Adrian!

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

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

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

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

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

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

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

The final resting place of two members of the infamous Doan gang, notorious outlaws and Revolutionary War Loyalists.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome’s legendary peephole vista is also a former Crusader stronghold.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.