The attic of a four-century-old canal house hides a clandestine church.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

A former seaside jewel built for the everyman is now simply a neglected art deco fortress.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

This humble historic facade hides a history of boozing and the gentlemanly sport of rat-fighting.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

Visit the site of a subway powered by nothing more than air--and lots of it.

The last remnants of what was once one of the world's grandest hotels can now be found in a Manhattan subway station.

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.