Khosrogerd minaret

Khosrogerd Minaret is a 12th-century tower located 10 kilometres to the west of Sabzevar, Iran, and is all that remains of the Silk Road town of Khosrogerd, destroyed by the Mongols in 1220 AD. It is an example of Seljuk architecture.The minaret was built around 1112 AD by the order of "Taj-o-dowleh Ab-ol-ghasem-ebn-e-saeed" during the time of Saljoughian, and is almost 30 metres in height.

On top of the tower are tablets in the kufic script, and diamond decorations. At the time of its construction it was one of the tallest spires in Iran. It was registered as national treasure of Iran in 1932.According to archeological researches, the tower is a free-standing spire which was built as a path-finding guide for caravans along the path to Abrisham, and served as guide for caravans.

Source: Wikipedia