A layered tribute to the work of mosaicist Isaiah Zagar.

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

America’s smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

This beloved marketplace mascot poops money and grants good luck.

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

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

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

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

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

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

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

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

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

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

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

One of Philadelphia's largest murals resides hidden under this bridge.

Huge masonic hall in Philadelphia with lavishly themed rooms.

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

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

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

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.

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

This sculpture of a fisherman spent six years at the bottom of the Schuylkill River.