This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The last bastion of Roman presence north of the Alps looms over a German town.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The ghostly remains of an accidental sea.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This stretch of beach along California's central coast is a busy highway for the largest seal in the northern hemisphere.

A popular winter vacation destination for migrating monarch butterflies.

The embalmed remains of the communist leader lie within a custom crystal coffin.

Hollywood's oldest hotel is the site of the first Academy Awards, the birthplace of Marilyn Monroe's career, and the home of Montgomery Clift's ghost.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

Wild West history in Hollywood style.

This museum is a music lover's introduction to the iconic venue.

This millstone commemorates a gruesome tale that may have been the source of the city's name.

This monument to those fallen in the World Wars is accompanied by a U-boat that Germany bought for a Deutsche Mark.

Where the lovelorn find a home for their sentimental keepsakes.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

A wall within the institution displays the names of 13,000 Jews who took refuge in the city during World War II.

An collection of Chinese propaganda posters from 1949 to 1979.

The once highest point in China blends symbolic design with a kick of adrenaline.

An out-of-place slice of France, smack in the middle of Shanghai.

An ancient fortification lives on in this Chinese city.

An eccentric folk art landmark made out of discarded bottles by an inspired "grandma."

The show's fictional Korean medical camp was created in the Santa Monica hills.

Frida Kahlo's childhood home, now a museum of her life and works.