The Vatican of the movie industry turned into an actual church.

Those belting out show tunes might not realize this piano bar marks the site where Thomas Paine died in 1809.

This historic building housed the surviving crew members of the Titanic, who were left destitute after the wreck.

The notorious headquarters of a corrupt political machine.

The oldest living tree in Manhattan comes shrouded in sinister legend.

The crown jewel of the Queens Museum is a nearly 10,000-square-foot architectural model of the city originally built for the 1964 World's Fair.

Once America's longest-manned military fort, now an abandoned hulk.

During the holidays, a vintage subway train whisks New Yorkers back in time.

Nondescript elevator doors open to reveal a stunning, surreal world.

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

This medieval castle was home to a known tyrant and features several hidden passages.

Located in the thermoelectric factory that once powered the entire city, this Portuguese museum is shockingly fascinating.

Elaborate tile work in this railway station tells the story of Portugal.

This historic streetcar system has been running since the 19th-century.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

A beautiful little museum hidden away in the heart of Barcelona holds a treasure trove of Ancient Egyptian artifacts

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

Visit the monolithic tomb of America's most famous general.

Manhattan's deadly West Side railroad, which killed hundreds of New Yorkers, is remembered by this simple plaque.

One of the city’s oldest watering holes was originally the home of a famous James Brown (not that one).

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.