Nursery with extensive collection of flesh-eating plants operated by the author of "The Savage Garden."

340 bicycles, 65 feet high.

This historic California cemetery holds the bodies of veterans of both the Civil War and the Donner Party.

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

This mysterious underground cave in Shropshire dates back to the 18th or 19th century.

The ancient mosaics here are considered among the finest in the world, and serve as a stunning record of Greco-Roman daily life.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Collection of fossils, plants, and ancient animals encased in amber.

This trio of Dominican cave lakes comprise a colorful biosphere of natural life.

Renowned restaurant tucked in a cave once occupied by buccaneers.

The haunting ruins of Jack London's dream house.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

An Italian hillside ghost town.

Submerged lava formations create incredible waterworks.

This industrial area was the dumping ground for massive amounts of trash, some of which washes up as tiny bits of sea glass.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

Stunning examples of Russia's 18th-century wooden architecture.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

The hermits of Karoulia protect their asocial lifestyles by living on the vertical face of a treacherous precipice.

The most metal church of all time was built in record time because of an international, pious pissing contest.

This abandoned Olympic skiing facility still bears the scars of the Siege of Sarajevo.

This abandoned Slovenian military barracks has become a punky-political art squat.