Hidden in the Chihuahuan Desert resides an amazing collection of petroglyphs.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

A tunnel with windows, so you don't miss out on the impressive views.

This quiet park's strange sedimentary spires were named after Kodak's color film.

Colorful sand dunes create a unique attraction in this part of Utah's red-rock country.

Although it also features red, orange, and variegated cliffs of Navajo Sandstone, this state park is often overshadowed by its more famous neighbor.

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."

Visitors to this arboretum are greeted by three smiling giants crafted from sustainable materials.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

An overlooked memorial honoring the local Washington residents who died in World War I.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

More than 21,000 images fill this overlooked gem of a prehistoric site.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

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

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

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

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

The largest tea plantation in Southeast Asia supplies gorgeous vistas alongside tea for the surrounding countries.