Toprak Kala is an excavated town dating back to the 1st to 5th cent. AD and is considered as the most important monument on Chorezm from the Kushan time. It's ground plan is 500m x 300m and it was surrounded by a wall made of bricks, 10 to 15 m high. The King's Palace in the north western part of the town was built on an elevated base rising about 15 m above the rest of the town. Three monumental towers, 25 m high, still exist. In front of the palace was the temple area with the holy fire. The town was divided by streets into several districts with blocks of dwellings with 150 to 200 rooms. The Kings's Hall covered an area of 280 squqre meters. The wall paintings and monumental clay sculptures were the works of a school of arts which could develop a particular Chorezmian style under the influence of Graceo-Bactrian art. The rooms of the palace had colourful wall paintings. The fortress is considered as the palace of the shah of Chorezm. In the ruins of Toprak Kale a great number of Kushan and Chorezm coins dating from the 2nd to the 5th cent. and small copper discs with portraits of the rules of Chorezm and written documents on wooden plates or on skins, the most ancient documents in this area, were found.
The ancient settlement Toprak-Kala is an outstanding monument of culture of Khorezm in 1-6th centuries A.D. The capital of Khorezm was here in the 3rd century A.D. Toprak-kala was discovered by by the Khorezm expedition under the guidance of S.P.Tolstov in 1938. According to the plan, the city had a form of a correct rectangle. The palace of the governor - a huge castle with three towers- was located in a northwest corner. The fire temple was in the south east from the castle. A long street dividing the city into two parts led from the fire temple to south direction. Lanes departing from it separated massive houses-blocks, forming the capital of the late slave-owning Khorezm.
Built in the 3rd century, the fortress was used as the residence of khorezmshakhs - governors of the country- up to 305 A.D. Numerous aggressive wars forced the governors to leave the residence, and the city gradually fell into decay.
Coins, fragments of ossuaries (Zoroastrian’s canopic jars), magnificent samples of art culture were found during archeological excavations: thin manufactured ceramics, wool, silk fabrics, gold ornaments and a necklace of 300 glass beads, paste, amber, corals, bowls.
Archeologists also discovered workshops manufacturing bows that made Khorezm famous. The architecture of the monument is a remarkable sample of town-planning and fortification art of ancient Khorezm. The governor’s palace with three towers is of particular interest. Three grandiose towers with rooms inside mounted 30 metres up, their height of 25 metres today is an evidence of advanced level of architecture development in Khoresm.
However the Toprak-Kala is famous not only with its unusual architecture but also with unique finds in ancient Khorezmian language, discovered at four building in the south-eastern part of the palace. Archeologists found 116 documents written with black ink on wooden plates and on leather rolls. Eighteen wooden documents remained in a very good state. Though documents are not completely read yet, their nature is already defined. These are economic documents from the palace archive. Three of the found documents had precise dates - 207, 231 and 232 AD.
Along with the archive, sculptures and painting also attract interest. It is not without reason that Toprak-Kala is named a museum of the fine arts of Ancient Khorezm. It is the unique completely dug out monument of architecture of Khoresm. The sizes and genius of an architectural design make Toprak-Kala one of the most unique monuments of Khoresm.