Abdullah Khan Kala is a mud-brick fortress on the edge of the Merv oasis, about five kilometres from the town of Bayramaly, and it makes a surprising amount of noise for something so silent. Its walls are enormous, rising out of the flat desert plain, and from the top you can see the pale shapes of other Merv monuments far away, all of them made from the same earth.
Merv, at its height a city that rivalled Baghdad and Cairo, lies in a sprawl of separate walled cities built across more than two thousand years. Abdullah Khan Kala belongs to the late phase, when Timurid rulers rebuilt the area after the Mongol destruction of 1221, one of history's grimmest massacres. It is a square fortress that served as a garrison and a symbol, with high walls, corner towers and a single gate. It was not the biggest part of Merv, but it is among the best preserved, and the clay has weathered into soft ridges and creases.
The ride is flat and straight. From Mary, thirty-odd kilometres to the west, the road runs through irrigated cotton and wheat, then out onto desert where the verge disappears into sand. Expect heat from May to September, sometimes over forty degrees, and wind that raises dust. The best time to come is spring, when the plain is briefly green, or early autumn, with low gold light. Sunrise and sunset do wonders for the brickwork.
Bayramaly, with about seventy-five thousand people, is the nearest place for fuel and food, and Mary is the larger option. Take water and a hat, because there is almost no shade at the site, and bring a camera for the silhouettes. Foreigners travelling in Turkmenistan need visas and, usually, a guide or transit permit, so organise that ahead of time. Locals are friendly and curious, and melon sellers on the road deserve a stop.