One of the oldest living oak trees in the Southeast.

Portlandia is the second-largest copper repoussé statue in the United States.

A wall of chewing gum moonlights as collective art.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

World War II bunker still standing on the New Jersey beach.

A historic presidential getaway on the continental United States' southernmost island.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Recently restored menagerie of Victorian-era beasts.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Where commuters walk through remnants of an ancient Greek necropolis.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

The original film set of Luke Skywalker's Tatooine home from the 'Star Wars' trilogy.

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.

A volcanic old faithful, Stromboli has been erupting continuously for the last 2000 years.