In a land of harsh deserts, feared bandits, and worse, few sites are as welcome as the kahn or fundaco. These stops on noted trade routes provide welcome respite from the hazards of travel. Though varrying in size from hundreds to tens of thousands of square feet, most are similar -- a tall, broad gate, big enough for camels and horses to pass through, opens into a square open-air courtyard. Fresh water is always provided, as are bedrooms on the upper level. Numerous stalls and doorways surround this courtyard, where traders and locals set up shop, hawking food and trade goods to the traveller. Whether staying for the night or for a month, the visitor to the kahn can expect rest, entertainment, and information on the road ahead.
Rulers build and maintain kahns in order to facilitate trade along their roads, but recent events such as the disintegration of the Abbasid Sultanate have left many of these stops in isolation. Rumors persist of a ghostly kahn that does not appear on any map, but rather materializes out of the desert for the weary traveler. Lured in by the promise of fine food and shelter, the traveler (or entire caravan!) is tempted by delights of food and flesh, only to awake in the middle of the desert, miles and miles from where they thought they were. Some are said never to return at all.
(I'm fascinated by the idea of the caravanserai. This seems like a RPG staple that I've never seen really developed, aside from the standard roadside inn. Historically, these things played an vital part in trade and would seem to serve as a wealth of adventure seeds.)