Turkey - Göreme National Park and the Rock Sites of Cappadocia

"In a spectacular landscape, entirely sculpted by erosion, the Göreme valley and its surroundings contain rock-hewn sanctuaries that provide unique evidence of Byzantine art in the post-Iconoclastic period. Dwellings, troglodyte villages and underground towns – the remains of a traditional human habitat dating back to the 4th century – can also be seen there." 

Source: UNESCO World Heritage