The territory of Kazakhstan has historically been inhabited by nomadic tribes. This changed in the 13th century, when Genghis Khan occupied the country as part of the Mongolian Empire. Kazakhstan, a Central Asian country and former Soviet republic, extends from the Caspian Sea in the west to the Altai Mountains at its eastern border with China and Russia. Its largest metropolis, Almaty, is a long-standing trading hub whose landmarks include Ascension Cathedral, a tsarist-era Russian Orthodox Church, and the Central State Museum of Kazakhstan, displaying thousands of Kazakh artifacts. Kazakhstan has an 'extreme' continental climate, with warm summers and very cold winters. Indeed, Astana is the second coldest capital city in the world after Ulaanbaatar. Although largest landlocked country in the world, Kazakhstan tourism industry is underdeveloped. International arrivals rose from 1.47 million in 2000 to 4.81 million in 2012. Among main tourist attractions, there are five World Heritage Sites in Kazakhstan and thirteen are on the tentative list.