One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

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

A winding district gerrymandered into the shape of a mantis.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

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

Once America's tallest structure, now a Baltimore landmark.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The land is home to swimming ponies and a legendary 18th-century treasure.

One of the only memorials dedicated to journalists who died in combat.

Built by the patriotic residents of Boonsboro in a single day.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A nostalgic bibliographic gem.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

Mausoleums, astronomy, and animatronic dinosaurs at this memorial to an assassinated American president.

The 25th President's marble casket can be visited in this classical Ohio tomb.

Memorials and tributes scattered across the university grounds remember a famous national tragedy of the Nixon era.

Ghost stories surrounded this “castle,” the only structure from a huge mansion that was never built.

Landmark dedicated to the plight of the American Indian in the 21st century.