I'm not a natural WHS lover but I still decided to write this because it seemed to me that here is lack of information of Bayanbulaq (Bayinbuluke) and Qarajun-Köldeneng (Kalajun-Ku'erdening).
In my opinion all 4 parts of Tengritagh (Tianshan) WHS are equally important because they reflect one of the most important OUV - biodiversity. Tömür(Mountain), Bogda(Lake), Qarajun-Köldeneng(Mountain Grassland-Forest), Bayanbulaq(Basin Grassland), each has their uniqueness.
Bayanbulaq
Bayanbulaq is located in a little basin between 2 branches of the mountains and has always been the traditional pasture of the Junggar people. The main attraction you can visit is the Bayinbuluke Grassland scenic area (entrance CNY 150), where rivers meander due to the Coriolis force. There is also a small Tibetan Buddhist temple here, which is currently almost the only permanent building on the grassland. (Originally there was also a town and other buildings, but they have been demolished and the residents have moved out)
The most convenient way to get here is to drive, especially the seasonry Duku (Maytagh-Kocha) Highway (an excellent way to experience the OUV of this WHS, although not in its area). There are many accommodation options in the town, but it is often difficult to find a room during the peak season. Overall, as an important stop in the middle of a road trip, it is worth spending half a day to a day here to enjoy the beautiful natural scenery.
Qarajun-Köldeneng
Qarajun is divided into 2 areas, both with stunning mountain grassland view. It is required to park their vehicles in the parking lot outside the area to tranfer shuttle buses.
Köldeneng is slight less visited, with coniferous distributed. You can drive in but the road situation is not good for sedans. (though I made it)
Actually these 2 parts are close to each other, tourists tend to visit them in 2-3 consequent days (you can surely stay for more days if you want, camping/trekking/horse riding cross is also popular options). They are all super popular attractions nowadays and there're long waiting queue for driving in during the peak season (summer). Make your plan before going!