The work is a historical and archaeological work, which sets out the results of new studies of stone defensive structures of the cities of Novgorod land - Ladoga, Oreshka, Korela, Tiversky town, Koporye, Yamgorod and Porkhov. In each of the mentioned cities defending the northern and western borders of Northern Russia, previously unknown military and civil buildings of the late 9th-16th centuries were discovered and studied, which made it possible to describe in a new way the development of stone fortification of the Russian Middle Ages.