Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

A hidden three-foot-wide house separates these two regal churches.

A majestic hotel for dreamers rises from the center of a fairytale wood.

One of the largest Roman settlements in Portugal.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Houses are tucked between, on, and underneath giant boulders.

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

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The greatest real estate coup of all time.

The origins of midtown Manhattan's anachronistic wooden farmhouse remain a mystery.

There are owls with glowing eyes in Herald Square.

Need to book a room at the Hotel Pennsylvania? Just dial up 6-5000.

The one-time epicenter of American songwriting is now a little remembered Manhattan commercial block.

Revolutionary War casualties fill the only 17th century structure remaining in Manhattan.

Possible relics of the ancient Roman city are hidden in this restaurant's façade.

This iconic tattoo shop has its own onsite museum with artifacts from the early history of modern body art.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.

Cheap pizza and all of your naughty bedroom needs housed in a stunning example of Art Nouveau architecture.

A museum collection honoring the long history of the FDNY is held in a disused Manhattan fire house.

This outdoor gallery of graffiti-covered walls pays homage to the past, present, and possible future of street art.