Though Khiva is about 2500 years old, it acquired its present appearance in the 18th – early 20th centuries. Khiva consists of two urban parts: the inner town Ichan-Kala and the outer town Dishan-Kala. From the very beginning the core of the city –Ichan-Kala, rectangular in plan, was enclosed in fortification walls.
For centuries these walls served ideally the purpose of the town’s defense. But in 1220 they were destroyed by Mongol invaders and in later period gentle slopes of the collapsed walls were used for burying the dead. In 1790 the wall was rebuilt by order of Khiva’s khan Muhammad-Amin-Inak. It was 1200 meters long, 7-8 meters high and about 6 meters thick at the base. Since Khiva stood at an important intersection of the Great Silk Road, there were built four monumental gates directing north, south, east and west. Ark-Darvoza gate located next to Kunya-Ark Citadel let in the caravans from the west.Kosh-Darvoza (‘Double Gate’) with two entrance arches faced south. Tash-Darvoza (‘Stone Gate) was built in the northern part of the city.
The most remarkable is the eastern gate Palvan-Darvoza (‘Hero Warrior’s Gate’), through which ran the road to the Amu Darya River and to the ancient trade town Khazarasp. The survived marble slab above the arch of the gate shows the date the construction was completed: 1221 anno hegirae (1806). Adjoining the gate is the gallery with six domes – a shopping arcade. Soon after the gate had been built, near it there appeared Allakuli-Khan Madrassah, caravanserai and a tim domed trading center. This was also the place where executions used to be carried out. Next to the gate, behind the Ichan-Kala walls, there was the Asian largest slave market. In 1842 a new fortification wall around larger area was built. Supervised by Mahammad Yakub Mekhtar, the construction was completed within 30 days. The wall was 6 kilometers long; it had 10 gates and a lot of turrets. Three out-of-town gardens – Rafanik, Nurullabay and Nurullabek – became part of the town. The larger ring of the town was then called Dishan-Kala (‘Outer Fortress’). Today only separate parts of this unique fortification structure remain. Yet these strong pahsa adobe walls narrowing to the top, are rather impressive. Every 30-50 meters along the length of the wall there are semicircular watching turrets; they seem to support the wall with their abutments. Looking at Khiva’s walls it is hard to believe that outside this well-preserved medieval town is the 21st century.