Premise: Situated on the route of the ancient caravans that brought goods from the Middle East and Central Asia, the sandstone citadel of Jaisalmer, protected by an imposing double set of bastions, rises like a mirage from the sands of the Thar Desert.

Hypothesis: The citadel of Jaisalmer is built of sandstone and located in the Thar Desert.
Relation: entailment