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

A charming beach town in Turkey captures all the colors of the rainbow.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Ottoman-era houses lovingly preserved.

Flames have been burning within this mountain for more than 2,500 years.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Naturally protected city carved from a rock face.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

A meow-velous tribute to a beloved street cat, made famous on the internet.

The ornate miniature mansions were built for Istanbul's feathered residents.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The natural hot spring that was integral to the creation of Canada's first national park.

With a floor made of thick glass, this observation deck offers a full view of Sunwapta Valley's mountains and rivers.

This First Nations monument is a peaceful spot with vast views of the Calgary prairie.

The granite head appears to be deep in thought and half buried in the ground.

A small and quirky museum hidden inside a fence.

Blackfoot petroglyphs of southern Alberta which date back as far as 7000 B.C.

A mysterious taxidermy man-beast of the seven seas.

The frozen bubbles that form on the icy surface of this Canadian lake contain enough methane to create a small explosion.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

A patch of contaminated land reclaimed as a scrappy sculptural oasis.