This small primate research island is teeming with playing, fighting wild monkeys.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

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

A glittering Thai Buddhist temple in suburban Pennsylvania.

This public space is speckled with the eerie remnants of a defunct amusement park.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.