World War II-era Nazi compound nestled in the Santa Monica hills.

This centerpiece of the Hollywood & Highland shopping center is a recreation of a long-lost movie set.

The blinking light atop the iconic landmark has been sending secret messages for decades.

This quirky UFO-shaped curiosity is often mistaken for the airport’s control tower.

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.

The space-age building is home to one of the few remaining rotating restaurants in America, and the only one that inspired a 1980s sitcom.

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

The beautiful 1920 Pantages Theatre remains hidden just underneath the LA Downtown Jewelry Exchange.

This opulent hotel has been visited by Spider-Man, Charlie's Angels, and the Ghostbusters.

Once strictly off-limits, this lower level housing curious and priceless vehicles of the Petersen Automotive Museum is now open to the public.

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

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

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

One of the first skyscrapers in Santa Monica, and a famous getaway for the Hollywood elite of then and now.

A second generation sun-powered marvel lights up the night.

"The only replacement for a DC-3 is another DC-3."

This 11th-century castle sits so low you can't see it behind the surrounding buildings.

An unassuming rod in the Netherlands was once the old standard unit of length for the entire Dutch empire.

One of the Leiden's oldest pubs is also the birthplace of the Heineken star.

This public library and its impressive collection of academic books have not changed since the 17th century.

An ancient Egyptian temple sits within a modern European museum.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

Science meets wall art to highlight the beauty of famous mathematical equations.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.