The Radkan Tower is a 25-meter-tall yellow-brick structure that lies in the mountainous region of Khorasan in northeastern Iran. Built in the 13th century, the purpose of this conical tower has long been a mystery. Today, it is believed to be a highly sophisticated astronomical structure designed by the great Persian scholar, Nasir al-Din al-Tusi. In this documentary film by Ehsan Mollazadeh & Hojjat Heidari, archaeologists and astronomers and animators combine their skills to help demonstrate to the viewer just how the tower was able to predict the turn of the seasons and the arrival of Nowruz, the Iranian New Year. This entrancing documentary reveals both the remarkable skills of the builders and the advanced scientific knowledge of the time.