Dig for your own trilobites in this goldmine of invertebrates.

A curious building honoring past and current members of a historic musical comedy troupe.

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

Hidden behind West Philadelphia rowhomes is a haven for migratory and local bird species both ordinary and rare.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

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

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

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

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

In the early 1800s, surgery was also a show.

The oldest surviving botanic garden in the United States.

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

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

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

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Ever hear of the Milazzo Cage?

A new sculpture calls attention to climate change in the centuries-old city it threatens.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

Although their purpose is unknown, these ancient Roman supporting arches showcase Hellenistic ingenuity.

Ancient, mysterious stone altars are hidden among wild woods in central Italy.

Production site for handmade clay bricks.

A beloved local artist has been honored with this statue of a man emerging from a toilet.

Old batteries and frog skeletons reside in this lakeside monument to Alessandro Volta.