A Yemeni man looks at a graffito of Socotra island during a graffiti campaign launched to call the world to stand by this UNESCO World Heritage island on a wall in Sanaa, Yemen, on May 31, 2018. As an UNESCO World Heritage Site, Socotra island is a Yemeni archipelago on the Indian Ocean, which has unique nature, trees, water springs and a strategic location. (Xinhua/ Mohammed Mohammed)???