The Islamic Republic of Afghanistan is a landlocked and mountainous country in South-Central Asia that is bordered by Pakistan to the south and to the east, Iran to the west, Turkmenistan, Uzbekistan and Tajikistan to the north, and China to the far northeast. The territory now forming Afghanistan was a pivotal region of the Silk Road and human migration. Archaeologists have found evidence of human habitation from as far back as 50,000 BC. Urban civilization may have begun in the area as early as 3000 to 2000 BC.