Gonbad-e Qabus tower is a monument in Gonbad-e Qabus , Iran , and a UNESCO World Heritage Site since 2012 .
The Tower in the central part of the city reaches 72 metres (236 ft) (including the height of the platform) .
The baked-brick-built tower is an enormous decagon building with a conic roof , which forms the golden ratio Phi , that equals 1.618 . The interiors contain the earliest examples of Muqarnas decorative styles . The decagon with its 3 meter-thick wall , divided into 10 sides , has a diameter of 17 m . The Tower was built on such a scientific and architectural design that at the front of the Tower , at an external circle , one can hear one's echo .
The tower was built in 1006 AD on the orders of the Ziyarid Amir Shams ol-Ma'ali Qabus ibn Wushmgir . It is located 3 km north of the ancient city of Jorjan , from where the Ziyarid dynasty ruled . The tower is over 1000 years old .
"This tall palace for the prince Shams ul-Ma'ali , Amir Qabus ibn Wushmgir ordered to build during his life , in the year 397 the lunar Hegira , and the year 375 the solar Hegira" .
Even though the inscription does not explicitly refer to the rumor that the tower was built for the tomb for the prince Ziyarid ruler , it is believed that the Sultan's body was put in a glass coffin and was suspended from the ceiling of the tower .
It has been registered a World Heritage Site , in the tower's upcoming 1,000th anniversary .
Gonbad-e Qabus or Gonbad-e Kavus is a city in the province of Golestan in Iran . The city tower was built with bricks representing a special art related to the 4th century (Hegira , or 11th century) . This tower which stands on a domed hill with 15 m height is located in the central (principal) park of Gonbad Kavoos city .
Robert Byron , the British travel writer and architectural critic , wrote that it was a photograph of the tower that motivated him to visit Persia . Seeing the tower , he maintained his high opinion of its qualities , writing in The Road to Oxiana , that 'the Gumbad-i-Kabus ranks with the great buildings of the world .