Ayaz Kala, Toprak Kala and the desert castles of Khorezm

Khorezm grew up in the delta of the Amu Darya, where the river spreads out before reaching the Aral Sea. From the middle of the first millennium BC, its people dug irrigation canals that turned the desert edge into farmland. To protect the canals, the fields and the trade routes, they built fortified settlements along the boundary between the oasis and the desert.

Over the centuries Khorezm was part of, or neighbour to, the Achaemenid Persian empire, the Kushan world and the nomadic powers of the steppe. When rivers shifted and canals were abandoned, the forts were left in what became open desert. That is why they survive so well: nobody built over them.

Much of what we know comes from the Khorezm Archaeological-Ethnographic Expedition led by the Soviet archaeologist Sergey Tolstov from the late 1930s, which mapped hundreds of sites from the ground and from the air.

Toprak Kala ("earthen fortress") was a royal city of ancient Khorezm in the first centuries AD. A rectangular walled town with a straight central street is dominated at one corner by the palace, raised on a platform about 25 m high. Its halls were decorated with wall paintings and sculpture. Excavators also found documents written in the Khorezmian language, among the earliest written records of the region.

Walk up to the palace platform for the view over the town plan, then around the outer walls. The site is open and unshaded; bring a hat.

Kyzyl Kala ("red fortress") is a small square fort from roughly the same period as Toprak Kala, about 65 m on each side. Part of its walls has been restored, which helps you picture what the other fortresses looked like when they were complete. It takes 20–30 minutes and is usually the first or second stop of the day.

Ayaz Kala is the most dramatic of the castles and the one most travellers remember. There are three parts:

• Ayaz Kala 1, on top of the ridge, the oldest, from around the 4th–3rd centuries BC. The climb up the sandy slope takes 15–20 minutes and rewards you with the widest view in the region: the Kyzylkum, the salt flats and the lake of Akchakul.
• Ayaz Kala 2, on a lower hill, a later fortified residence with remains of rooms and gateways.
• Ayaz Kala 3, a large rectangular enclosure on the plain at the foot of the hills.

The best light is the last hour before sunset, when the walls turn orange and the desert below goes blue. That is the main reason to stay the night at the yurt camp.

Below the fortress is a yurt camp with traditional felt yurts, shared washrooms and a dining yurt. On a day trip it is where we stop for lunch. As an overnight stay, it gives you dinner under the stars, the sunset climb to Ayaz Kala and sunrise over the desert. The camp is seasonal and closes in the coldest months. Nights can be cold even in spring and autumn, so bring a warm layer.

Some travellers add a short camel ride near the camp. Ask us whether it is available on your dates.

• Guldursun Kala, a large fortress near Beruniy, with the legend of a princess who betrayed her city to an invader for love, and was punished by him for it.
• Chilpik, a ring-shaped Zoroastrian dakhma ("tower of silence") on a hill above the Amu Darya, on the road between the fortresses and Nukus. Zoroastrians exposed their dead here so that the bones could be collected without polluting earth or fire.
• Big Kyrk Kyz, Koy-Krylgan Kala and Janpyk Kala, less visited sites that need a 4×4, a specialist guide and more time. Ask us to include them.

• Heat: from June to August, visit Toprak Kala and Kyzyl Kala early, rest in the camp at midday and climb Ayaz Kala late.
• Shoes: the slopes are loose sand and crumbling earth. Wear closed shoes.
• Respect the sites: don’t climb on fragile walls or take pottery shards; these are protected monuments.
• Facilities: apart from the yurt camp there are few facilities near the sites. Carry water and snacks.

Our desert fortresses day tour from Khiva covers the classic three; the 4-day Aral Sea & Karakalpakstan journey continues north to Nukus and Muynak.