HIissar valley is a wide inter-mountain trough, about 70km long and 2-18km wide, through which the Kofarnihon, Qaratag, and Shirkent rivers run.
This area was populated as early as the Stone Age in 4th-3rd millennia B.C. Later it became a part of Bactria and then of the Greco-Bactrian and Kushan states. Numerous archaeological finds of remains of ancient settlements in the form of man-made round and rectangular embankments, known as teppa by the local population, are evidence of that. Other archaeological monuments - madrassahs, mosques, burial grounds, remains of irrigation canals, etc. are also known.
In the Middle Ages, Hissar was already famous in the Middle East for its craft production and had a rich market. The royal town was one of the 28 possessions of the Bukhara emirate. By the early 20th century Hissar was in a state of severe decay.
At the site of the ancient town, archaeological and architectural monuments of different eras are now preserved, occupying an area of about 86 hectares.
An original architectural complex formed around the Hissar fortress, where the palace of the East Bukhara governor-general, one of the most influential aristocrats of the Bukhara emirate, was located, is of particular interest.
Baked-brick gates with two cylindrical towers connected by a lancet arch have been preserved from the outer ring of the fortifications. A hill slope where the fortress was once located was built in the form of brick-faced terraces. The terraces and stairs on each side which led to the gates were destroyed. The Hissar fortress gates are similar to Bukhara's 18-19th-century gates in their outer appearance and features of their construction .
The best-preserved buildings are the old (16-17th century) madrassah (madrassah-i kuhna) - a dome-shaped building with a wide courtyard and hujra (cells) inside, a library building and a new madrassah (madrassah-i nav) from the 17-18th centuries which only has two-stories on its front left side. All the structures resemble complexes in Bukhara and Samarqand and have been restored and nowadays are available for visitors to see something resembling the original. In the early 20th century madrassah-i kuhna had 100-150 students. Classes in the madrassah ended in 1921.
To the south of the old madrassah lies the 16-17th century Mahdumi A'zam mausoleum. Mahdumi A'zam means "Greatest master" and is not so much a name as a title or a nickname. It is interesting that in Central Asia there are several complexes under this name connected with a variety of real people, states and religious figures. Researchers have yet to identify who exactly is buried in the Hissar mausoleum, although there are already several theories and guesses. There is one other remarkable local monument, the 12-16th century Sangin (Stony) domical mosque. The mosque was so named due to the fact that the lower half of its walls were built of stone. The unique feature of this structure is the presence of four resonating chambers below the dome frames in the shape of bottomless ceramic jugs embedded in the brick mass. The resonating chambers were intended to improve the acoustic characteristics of the mosques' interior where sermons and praying took place.