Kolomna Kremlin is a very large fortress in Kolomna, Russia. The stone Kolomna Kremlin was built from 1525–1531 under the Russian Tsar Vasily III. Before its reconstruction in 1531, the Kolomna Kremlin was made of wood. On its territory there are many Russian churches and monasteries: The Uspensky cathedral, the Voskresenky church, the Spassky monastery (14th century), and a number of others.