One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

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

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

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

A layered tribute to the work of mosaicist Isaiah Zagar.

Elevated freight railway turned wildly successful urban park.

Dramatic river bend surrounds a natural red-rocked pedestal.

World's first "penitentiary," meant to be humane, drove men insane.

A reversed traffic signal that was once violently misinterpreted as a statement on British-Irish relations.

This Art Deco fortress in upstate New York gives Manhattan's vaunted examples of the style a run for their money.

Surprisingly aquamarine waters fill deep lakes formed at the end of the last ice age.

A Frankenstein blend of science and art allows one tree to produce 40 different types of stone fruit.

The alley connecting two of country music’s most historic venues has a rich history of its own.

This quirky local sculpture is quite literally a fish out of water.

This popular park is home to a sea serpent sculpture that now overshadows the twisted history of its creation.

The grave of America's 11th president is not in some grand monument but instead it's hidden away on the grounds of the Tennessee Capital.

One Confederate statue that accurately reflects the ugliness of its subject.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

This replica of the Greek structure is in the heart of Nashville.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.