As the Dead Sea continues to deplete, massive sinkholes open along its banks.

This unassuming oasis elevated just above the busy streets of Jerusalem offers one of the best views of the Old City.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

The bluer than blue waters in these natural Israeli caves are reached via the world's steepest cable car.

The restored and active Victorian-era final resting place of San Francisco.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

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

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

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

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

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

A giant can of fruit cocktail is all that remains of what was once the world's largest cannery.

The oldest house in the capital of Silicon Valley.

It took years to decode its mysterious messages.

The largest permanent Monopoly board makes one of the longest games even bigger.

An extensive collection of ancient Egyptian artifacts and mummies.

The headquarters of a secretive order is also a beautifully-designed park.

800 apricot trees honor Silicon Valley's agricultural history.