This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A wondrous old library overlooking the nation's capital.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

Located at the former Lorton Prison the Lucy Burns Museum tells the story of the 91 year history of the prison including the dark chapter of its involvement in the women's suffrage movement.

A 13,000-year-old mastodon skeleton was found during the construction of a 19th-century New York mill.

Two monstrous warehouses. One now holds priceless works of art, the other stands abandoned and dilapidated.

A mysterious, abandoned building rotting on the Brooklyn waterfront.

This restored log building was one of the first toll booths for travelers along the Northern Turnpike.

These small house replicas have stood proudly since the 1950s, even as the property has changed hands.

An imposing pair of sphinxes stand guard outside this Egyptian Revival tomb.

The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

Intricate storybook scenes are tucked inside these shadow boxes, which are tucked inside a library in the Pocono Mountains.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.