The beautiful, broad valley of the Karkara River is an age-old summer pasture for herds from both sides of what's now the Kazakhstan-Kyrgyzstan border. From Kegen, 250km by road east of Almaty, a scenic road heads south up the valley to Karkara village, and then on to the border post about 28km from Kegen. The road, which is normally open from about April to October, then veers west towards Tup and Lake Issyk-Kol in Kyrgyzstan. No public transport reaches the border, but minibuses leave Almaty's Sayakhat bus station at about 7am daily for Kegen (five to six hours), and from Kegen you can get up the valley and into Kyrgyzstan either by hitching or by taxi. At San-Tash, 19km into Kyrgyzstan, you can find a bus or a shared jeep to Tup or Karakol.
Be sure to get your Kyrgyz entry stamp at the border. From late June to late August, mountain tourism company Kan Tengri maintains a summer base camp at about 2200m on the Kazakh side of the international border. Primarily a staging post for treks and climbing expeditions to the central Tian Shan, the camp offers tent accommodation to all comers, with hot showers, a cafe and a bar. A three-day trip from Almaty, including a helicopter flight to Khan Tengri. Contact the company at least one week in advance and ask about the paperwork needed, as the track to the camp passes through some Kyrgyz territory, and a borderzone permit may be needed for the helicopter trip.