Elevated freight railway turned wildly successful urban park.

An enormous, inside-out glass globe built in 1935.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A terrific purveyor of natural history objects and curios.

A huge musical instrument played by the ocean.

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

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

South Korea's largely symbolic, barely used gateway to the North.

Secret North Korean passage discovered below the world's most dangerous border.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

The site of the climactic scene from the classic horror film is now a historic landmark.

A wondrous old library overlooking the nation's capital.

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

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

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

Largest Roman Catholic church in North America.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

The United States Capitol's former columns still stand.