Windmills are towers that are built for ventilation and cooling on the roofs of houses. Ventilators are also built above reservoirs and mine openings for ventilation. In houses, cool air is sent from the fan, which is the basic type of air conditioning, to the rooms on the ground floor or basements. Windmills are elements and symbols of Iranian architecture, but today they are used in many countries of the Middle East.

دژ رودخان یا قلعه حسامی نام قلعه‌ای است متعلق به دوره امپراتوری ساسانی که بر فراز ارتفاعات جنگلی شهرستان فومن در روستای رودخان ساخته شده و ۲٫۶ هکتار مساحت و ۶۵ برج و بارو و دیواری به طول ۱۵۰۰ متر دارد. دژ رودخان در ۳۰ کیلومتری شهر فومن است. اهالی روستای قلعه رودخان به تالشی تکلم دارند برخی کارشناسان، ساخت قلعه را در دوران ساسانیان و مقارن با حمله اعراب به ایران دانسته‌اند.Rudkhan Fortress or Hesami Castle is the name of a fortress belonging to the Sassanid Empire period, which was built above the forest heights of Foman city in Rudkhan village and has an area of ​​2.6 hectares and 65 towers and ramparts and a wall 1500 meters long. Rudkhan fortress is 30 km away from Fuman city. Residents of the village of Rudkhan Castle speak Talshi. Some experts have considered the construction of the castle during the Sassanid era and parallel to the Arab invasion of Iran.