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 (when it became Turkey's largest han). 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.
An ornate doorway leads to the atmospheric ahır (stable), with arches, domes and pillars in the pigeon-soundtracked gloom.
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.