Ride the subways of yesteryear.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Doris Duke's lasting collection of Islamic Art, hidden in a Hawaiian paradise.

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

One of Ireland's most infamous prisons for rebels including men, women and children.

Baroque celebration of the end of the Great Plague of Vienna.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Statue in Salem of the woman who starred as the witch Samantha in the sitcom "Bewitched."

An eccentric inventor's castle home with its own indoor weather system.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

San Francisco's newly reopened hands-on science museum.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Climb inside an iron crystal magnified 165 billion times its normal size.

A little sculpture with a large wardrobe.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

A beautifully well-preserved ancient Roman villa.

Beautiful views and Roman-style statues on the Italian coast.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

A hand-built folk art installation covered with messages of God's love.

The ghostly remains of an accidental sea.