A monument celebrating the idea of reaching inaccessible places.

San Francisco's first World's Fair, dedicated to the wonders of California.

Once the site of speeding horses, now home to picnickers and public concerts.

Exact replica of the ancient monument, but much, much lighter.

A massive sea stack famous for its appearance in The Goonies.

One of the largest public housing complexes in New York once visited by Eleanor Roosevelt.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

27-room home built with the fortune of a sugar magnate.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

At 207 feet, one of the world's longest continuous escalators.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

This turn of the century masterpiece has a mysterious goaty interloper.

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

Steadily reminding Czechia of its past.

Unrepaired walls from a 1920 anarchist bomb attack.

On the Hudson resides one of the largest clocks in the world.

Only hotel where you can legally launder money.

The site where Poe “in great distress, and ... in need of immediate assistance” likely died.

A 60-room castle constructed by a horse-racing heir.

Ruins of a once-prized railroad station in New York.

Radioactivity still cause for concern at this urban explorer's paradise.

Where a staggering 747 ships were constructed during World War II.

A decommissioned military complex that's now a modern industrial park.

One-time winter retreats of prolific inventor Thomas Edison and his friend Henry Ford.