The largest caravanserai in Anatolia, the Sultanhanı was constructed in 1229, during the reign of the Seljuk sultan Alaaddin Keykubad I, and restored in 1278 after a fire. Through the wonderful carved entrance in the 50m-long east wall, there is a raised mescit (prayer room) in the middle of the open courtyard, which is ringed with rooms used for sleeping, dining and cooking.
The site is a popular stop for tour groups, and you may field invitations to visit the nearby carpet-repair workshop. If you resist such offers, you could easily explore Sultanhanı in half an hour.