Khmer Rouge's high security prison.

5,000 skulls in memorial to those killed by the Khmer Rouge.

One of the biggest markets in Asia, under one of the continent's largest domes.

The capital of Cambodia is named after the hill on which this ancient temple complex stands.

Common all over Japan, kōbans are small community police boxes, and now one is guarding one of L.A.’s megamalls.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

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

Single runway interrupted by a busy road that cuts across its middle.

The only road through the heart of Glacier National Park.

This 19th century cyclorama acts like an analogue time machine to a different era.

Ugly 18th-century dwarf statues living in a perfectly landscaped Austrian garden.

A lush indoor jungle fills this bustling Madrid transportation hub.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This too-low North Carolina railroad trestle is still a notorious big rig executioner.

A small church in Uppsala hides the grave of a renowned 18th-century astronomer.

Legend has it this spring formed at the spot where a medieval Swedish king was killed.

The first thermometer made with the almost-universal temperature scale is backwards.

A large collection of ancient runestones decorates this university courtyard.

Legend says this fabled well held part of a mythical Norse tree.

This mysterious runestone embedded in a church wall is linked to the medieval cult of Saint Erik.

The official meeting point for the oddly named governing assembly of ancient Sweden.

Uppsala's adorable feline sign celebrates a popular children's book set in the Swedish city.

Ancient burial grounds of the wealthy.

The second oldest anatomical theater is housed in a museum of curiosities.