The last remaining building in Washington, D.C., built by H.H. Richardson, one of America's most iconic architects.

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

When it comes to handsignals (and colonialism) rock always beats scissors.

The most accurate timepiece in the world.

A World War II–era submarine museum where visitors can spend the night aboard.

Dating back to the 1800s, two imposing buildings in Michigan have had countless transformations over the years.

A massive collection of vintage cars in an industrial-style building.

This nearly 200-foot tall limestone stack offers visitors amazing views and a chance to meet Paul Bunyan and Babe the Blue Ox.

This was the first ever National Lakeshore, established in 1966.

The "plyscraper" is the world's tallest building made predominantly out of wood.

The world’s oldest active sailing ship.

This rusted car found in Petrified Forest National Park's Route 66 exhibit may be the most photographed abandoned car in the country.

The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

This museum shaped like an inflating balloon celebrates the sport’s buoyant achievements.

An abandoned warehouse turned art sanctuary in New Orleans.

Come for the 14-foot-long taxidermy alligator. Stay for the mini costumed gators shooting pool.

Collection of scores of race cars from the 1900s to recent lovingly maintained and displayed.

These medicine cabinet staples are part of the museum's collection of everyday objects.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

Trace the history of the nation’s early days at the site of America’s oldest stock exchange.

This overlooked courtyard and museum celebrate Benjamin Franklin's life and achievements.

The Fabric Workshop and Museum showcases fabric and mixed media work by artists of great international renown as well as local and outsider artists.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.