The border with Pakistan runs eastward from Iran through the Chagai Hills and the southern end of the Registan Desert, then northward through mountains. It then follows an irregular northeasterly course before reaching the Durand Line, established in 1893. This line continues on through mountainous regions to the Khyber Pass area. Beyond this point it rises to the crest of the Hindu Kush, which it follows eastward to the Pamir Mountains. The Durand Line divides the Pashtun tribes of the region between Afghanistan and Pakistan. Its creation has caused much dissatisfaction among Afghans and has given rise to political tensions between the two countries.