Kazakh expedition reaches Tash Rabat

The expedition "Following Shoqan Walikhanov’s Caravan Route" arrived to the ancient caravanserai Tash Rabat late after dark.

Tash Rabat initially served as a prison, as there was a dungeon in the last room. But in the time of Shoqan Walikhanov the building served as a place for travelers to stay overnight.

But Tash Rabat was located 18 kilometers away from the Silk Road, which made it to remote for a convenient place for a night’s lodging. Then what was it?