Situated 10km south of Tokmok, the Burana Tower is all that remains of the ancient city of Balasugin, set at the foot of the Shamshy valley.  
The city was established in the 10th century on the site of an older settlement, and was the birthplace of the philosopher and poet Jusup Balasugyn (1015) who wrote an epic poem called Katadgu Bilig ("The knowledge which brings happiness"), which has been translated into several languages including a recent translation into English by Walter May.
With Kashgar, Balasugin was one of the capitals of the Eastern Khanate when the Karakhanid state split up. (The capital of the Western Khanate was Samarkand.) It was spared from destruction by Genghis Khan's Mongols, and renamed Gobalik ('Good City') in the 13th century, but it lost its importance and had disappeared by the 15th century.
There were major archaeological surveys of the site during the twentieth century and archaeologists discovered that the town had a complicated layout covering some 25-30 square kilometres. There were ruins of a central fortress, some handicraft shops, bazaars, four religious buildings, domestic dwellings, a bathhouse, a plot of arable land and a water main (pipes delivering water from a nearby canyon). Two rings of walls surrounded the town.
Although the Kharakhanids (who built the city) practiced Islam, they were tolerant of other religions and there are some examples of early Christian (Nestorian) inscriptions.
The entire museum complex today covers some 36 hectares. It includes the tower itself, reconstructions of mausoleums found on the site, a mound that is all that remains of the palace/citadel, a collection of balbals (grave markers used by nomadic Turkic peoples who used to roam Central Asia) and petroglyphs (paintings on stones), and a small museum.
The tower is believed to be a minaret and, if so, it is the oldest in Central Asia. The name Burana itself is probably a corruption of the Turkic word murana (minaret). A similar construction is preserved at Uzgen, in the south near the Uzbek border, complete with the domed crown and doorways from which the muezzin would call the faithful to prayer.
Originally 45m tall, however only the bottom 25m remains - the top was lost in an earthquake in the 15th century. The tower has an octagonal base and on this was constructed a conical tower. On the outside of the tower is pattern of relief work in brick. The diameter at the bottom of the tower is 9.3m and the top is 6m across. The remains were "cannibalised" by local people who took the bricks from the base for their building - photographs of the tower before reconstruction in the 1970s can be seen in the small museum and show this clearly.
Inside is a narrow spiral staircase that is said to be original, leading to the top. Access would have been by removable stairs or through the roof of the mosque - now there is a metal staircase leading to the door which is nearly 7m above ground on the southern side. From the top it is possible to get a good view of the Chu valley and Tokmok. Also, it is possible to make out the lines of the walls of the settlement in the fields surrounding the tower.
At the foot of the tower are some reconstructions of the foundations of several ancient mausoleums made out of burnt brick. These foundations were uncovered in the 1970s. The different shapes and sizes indicate the different status and numbers of occupants.
Nearby is a small hill, measuring 100m square and 10m high. It apparently hides a palace complex (or a temple - the archaeologists aren't sure), which existed in the 10th century - that is before the town itself came into being.
A little further away is a collection of balbals (small statues of the dead - gravestones of the nomadic Turks) dating from the 6th century, and petroglyphs dating from the 2nd century BC, brought and placed here from all around the Chu valley. There are other collections around the Chu valley and in Southern Kazakhstan.
The small museum contains some artefacts recovered from the site (jars, coins, a board game), but it is sometimes claimed that the best articles were removed a long time ago to Moscow or St. Petersburg. In the Shamshy valley itself a wide range of Scythian artefacts have been discovered, including a heavy golden burial mask.
From the Tower, it is possible to head into the mountains to a picturesque valley to the Kegeti or Shamshy gorges.