Construction of the stone Kremlin of Nizhny Novgorod began in 1500 with the building of the Ivanovskaya Tower; the main work commenced in 1508 and by 1515 a building was completed. The oak walls that formed the old fortifications were destroyed by a huge fire in 1513. The two kilometer wall was reinforced by 13 towers (one of them – Zachatskaya – was on the shore of the Volga; not preserved, but was rebuilt in 2012).