(CNN) — Surrounded on all sides by epic mountain scenery and with a 500-year-old fortress at its ​center, the city of ​Chefchaouen -- or Chaouen for short -- is becoming a new "it" place on​ Morocco's tourist trail. ​​

Yet​ it's not the mountains or the "Game of Thrones" architecture that travelers come in their thousands to see.

It's the color -- a gorgeous blue rinse that covers not only Chaouen's houses but its mosques, government buildings, public squares and even its lampposts and trash cans.

The custom dates back to the 15th century, when Jewish refugees fleeing the Spanish Inquisition settled in large numbers in Chaouen.

They brought with them their tradition of painting things blue to mirror the sky and remind them of God.

Photogenic mecca

Chaouen's Jews may have moved on, but the practice of painting things blue lived on.

It struck a chord with the first wave of Western backpackers that hit Morocco in the 1960s and has drawn travelers ever since.

The booming tourism industry has brought prosperity to the city.

In 2011, Giorgio Armani filmed a TV commercial in Chaouen.

Last year, Moroccan news outlet Aujourd'hui reported Eric Clapton was looking to buy a home here.