Rayen Castle (Persian: ارگ راين‎‎ Arg-e Rāyen) is an adobe castle in 100 Kilometers south of Kerman province, Iran. It is situated on the skirts of the mountain Haraz. The medieval mudbrick city of Rayen is similar to the Arg-e Bam city which was destroyed in an earthquake in December 2003. Rayen displays all the architectural elements of a deserted citadel. It is extremely well preserved, despite numerous natural disasters that have destroyed similar structures nearby, and it is one of the most interesting sites in Iran.[citation needed]

Rayen Castle was inhabited until 150 years ago and, although believed to be at least 1,000 years old, may have foundations from the pre-Islamic Sassanid era. According to the old documents, it was situated on the trade route, and was one of the centres for trading valuable goods and quality textiles. it was also a centre of sword and knife manufacturing, and later on, also guns.existence of a waterfall near the city, the Haraz mountain with 4501 meters of altitude, several fruit gardens, the mines of green and pink marble, Sodium Solphate, and several thermal springs, it’s become and attractive touristic destination. During the reign of third Yazdgerd, the Sasanid King, Arabs could not conquer this city thanks to its high walls supporting the counterparts of the city.