Fortified frontier defences of former Russian principalities, known since the 12th century
Construction
Construction of Zasechnaya cherta
Fortified frontier defences of former Russian principalities, known since the 12th century
- 1100s – 1100s
- Europe
Construction
Fortified frontier defences of former Russian principalities, known since the 12th century
Fortified frontier defences of former Russian principalities, known since the 12th century