The world’s first penitentiary, meant to be humane, drove men insane.

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

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

Century-old shop, specializing in Occult products.

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

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

This beloved marketplace mascot poops money and grants good luck.

A local prank turned town icon.

Pluto is still considered a planet in Ithaca, New York.

The world's largest piece of copyrighted artwork.

Two thousand artifacts from around the world collected by one woman who loved to travel.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

One of the few remaining monuments dedicated to South Boston's Irish heritage.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

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

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

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

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

A layered tribute to the work of mosaicist Isaiah Zagar.

The Boston square dedicated to the dark poet who was born nearby.