Long before air conditioning, Persian architects found an ingenious way to cool off.

The ancient abodes are a testament to human ingenuity amid harsh climates.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A floating cat sanctuary on an Amsterdam canal.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

This impressive clifftop temple was once at the center of an international custody dispute.

The only town in the world with two exclamation points in its name.

The California secessionist movement has its own foreign embassy, in Russia of all places.

An abandoned early-20th-century boomtown sits within the Calico Rock city limits.

When life gave this firefighter a forest fire, he made a rough-hewn sculpture park using a chainsaw.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Raging waters have created a strange geological site that looks like something off of a progressive rock album cover.

At this faithfully preserved medina off the Moroccan tourist circuit you can walk through six centuries of history in one day.

A massive underwater sinkhole made famous by Jacques Cousteau.

The ruins of an abandoned crematorium haunt an eerie deserted German cemetery.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

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

Where manatees are the snowbird vacationers in these balmy Florida springs.

A 70-foot-deep ice cave formed by lava from Mt. Fuji on the edge of Japan's "Suicide Forest." 

The gargoyles and grotesques of the 21st century are here—22 emoji built into a new building in the Netherlands.

A grassy pyramid named after a French battle.