Look closely and you’ll notice that the color changes a third of the way up the tower.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

The "lovely red Vega" of the legendary record-settling pilot.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

One small town in the Pacific Northwest transformed itself into a Bavarian-themed tourist destination.

This triumphal 16th-century arched gateway leads to the oldest street in Palermo.

Thousands of well-dressed mummies below a monastery.

Pilgrims each carried a brick to the top of Mount Monserrate to help build this historic sanctuary in Colombia.

Cathedral carved out of salt, located a mile below the earth's surface.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

Minimalist modern art on a repurposed military base in rural Texas.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

A Prada store in the West Texas desert that is never open for business.

This quirky hot springs town known to locals as "T or C" was named after a radio show.

This is one really big nut.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

There are eight natural springs around town, each with a slightly different taste.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.