Rayen castle, or Arg-e Rayen is an adobe castle in Rayen town in Kerman, you can visit the medieval mud brick city of Rayen, Rayen is quite similar to the Arg-e Bam. Rayen displays all the architectural elements of a deserted citadel. It appears extremely well preserved, considering the numerous natural disasters that have been destroying similar structures nearby, and it is one of the most interesting historical sites in Iran. The fortress at Rayen is similar in outlook and construction to the fortress at Bam, while been younger in age. It is thought to be a Sassanian era (224 CE – 649 CE) fortress. Like Bam, Rayen fortress was in use until about 150 years ago.