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

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

A completely round house designed for the Atomic Age.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Tucked in the back of this amazing antique store is an important piece of medical history.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

Step inside Lucy, the world's largest "elephant."

Memorial built in 1922 in remembrance of WWI casualties.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

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.

Yo, Adrian!

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

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

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

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.