A marvel of Byzantine engineering under the streets of Istanbul.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

A homage to the King at the hotel where he revived his career.

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.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

There are lots of hands and feet stamped in the cement in front of Grauman’s Chinese Theater, but Mel left behind something extra.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

World-famous, Pink's still manages to keep its prized cult fetish status.

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

One of the most elaborate displays of Jellyfish is on display at the aquarium.

Quirky Welsh observatory unites art and science.

These murals stand as reminders to the troubled history of this Northern Ireland city.

These engineering masterpieces are a dominant feature of the Belfast skyline.

The last Victorian market in Belfast.

One of the largest lenses of its kind ever created, this former ship beacon has been brought down to Earth.

This massive monument has been telling the time for 150 years—at a slight angle.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

A beloved upside-down beacon off the coast of Northern Ireland.