This conically spired 25 m brick tower has baffled visitors for centuries. If it was a tomb or a coronation spot. Archeo-astronomers say that it was a highly sophisticated instrument for studying the stars, built in 1261 by astronomers led by Khaje Nasir Al-Tusi. The tower is in a field 3.1 km east of Radkan village along 22 Bahman st.
The height of the Radkan Tower is 35 meters, its internal diameter is 14 meters and its outer diameter is 20 meters.