The Spasskaya Tower was build under the guidance of Pietro-Antonio Solario in 1491, was rectangular in form and approximately half its present height. In the 16th century it was fitted with a clock and in 1625 the Russian architect Bazhen Ogurtsov built the octagonal multitiered turret which now surmounts the rectangular tower. A new clock was built on the turret equipped with a revolving face and a carillon by the Englishman, Christopher Halloway. The bells of the carillon were cast by Kirill Samoilov. In the reigh of Peter the Great the clock was replaced. The clock we see now was installed in 1851-52.
The lenght of the minute hand on the clock is 3.28 metres. The tower is 67.3 metres high.