Fortified walls and towers of Rostov Kremlin

Rostov the Great reached the peak of its power in 13 century, shortly before Mongol-Tartar invasion. But after that the city lost nearly all its previous political influence. However, Rostov was the seat of the metropolitan for several more centuries. Having a big influence and being in the center of ancient Christian cities metropolitan Iona decided to erect for himself a strong fortress with defensive walls and towers.