270 million year-old forest of stone.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

A canvas of crops grow from vibrant red soil in this terraced farmland.

A fifth-century temple improbably built into the side of a cliff.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

This South London cemetery holds the remains of more than 15,000 people.

Remains of the old fortification along the Western border of the USSR, now an elaborate defense museum.

Hidden beneath the streets of London is a secret subway that only carried mail.

The villagers of the coldest inhabited place on Earth adjust to unique challenges presented by day-to-day living.

This museum boasts a bucket of teeth and tells the tale of a 20th-century dental circus.

Impossibly life-like natural history models created out of glass by a father and son.

A stairway to heaven, or to nowhere at all.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

A serene space tucked amid the skyscrapers of Hong Kong's bustling financial district.

A few dilapidated structures are all that remain of this deserted former silver mining town.

These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

Monkeys lounge around at this 13th century temple.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

A striking 12th-century-style castle built on the edge of a cliff.