A Yemeni worker cleans the yard of the tourist site of the Dar al-Hajar (Rock Palace) on World Tourism Day at the village of Wadi Dhahr on the outskirts of Sana'a, Yemen, 27 September 2020. The historical five-storey palace of Dar al-Hajar (Rock Palace), one of Yemen's most popular tourist destinations, was built in 1786 AD, perching atop a rock pinnacle on the outskirts of Sana'a. World Tourism Day is commemorated each year on 27 September with this year's theme focusing on 'Tourism and Rural Development'.