Guides claim that this small, lonely mud compound with four little towers is a caravanserai (a traditional inn with a courtyard for camel trains). In fact it appears to be a recent contrivance and acts as the organisational post for the Lut Ultra-Marathon race team. At other times it makes a handy marker as one of the better places from which to wander a short way into the Kaluts on foot without hiring a 4WD.
It's on the main Nehbandan road, 3km east of Kalout.