© Istockphoto|Petra, Giordania 

© Istockphoto|Matmata, Tunisia 

© Istockphoto| Setenil de las Bodegas, Cadice, Spagna

© Istockphoto| Matera, Basilicata 

© Istockphoto|  Cliff Palace, Mesa Verde, USA

© Istockphoto| Uchisar, Cappadocia, Turchia 

© Istockphoto| Kandovan, Iran

© Istockphoto| Ajanta, Arrangabad, India

© Istockphoto| Al Hajjara, Yemen

© Istockphoto| Vardzia, Georgia