A plaque marks the house in Stockholm where the French philosopher René Descartes lived up until his death.

Several cannonballs of mysterious origins decorate two buildings in Stortoget's main square.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

Stockholm's tiniest statue is of a small boy looking at the Moon.

Outside a Viking museum sits a modern-day runestone made by a Swedish runemaster using traditional methods.

Sweden's "good old days" painstakingly re-created in a model village.

A former suicide bridge is now accumulating symbols of love instead of a body count.

The library's graceful rotunda is like a bibliophile's temple.

This giant crucifix is like U2's Joshua Tree for Swedish death metal fans.

Stockholm's narrowest alley is barely over two feet wide.

A wooden street sign is the last remnant of this 400-year-old alleyway.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Come face to face with the ferocious visage of the serpent-headed mother goddess of the Aztecs.

These biodiverse university gardens form a green oasis amid the urban chaos of Mexico City.

The only castle in North America to ever house European sovereigns.

Part bookstore, part café, and part forest.

One of the world's tallest statues is also one of its most hated.

Moscow's imposing monument to the Space Age.

Thanks to a spelling mistake this bizarre beaver-tiger hybrid became the symbol of a Siberian town.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

This historic hotel invented the chocolate brownie.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.