Defending a Russian wooden fort

Клуб ВИР "Лейб-гвардии Преображенский полк, 1709"  
These are some interesting photos. They say 'It was the event in the town of Osa on Kama river, West Urals region. It used to be a small fortress on the rout to Siberia. In 1733 Vitus Bering, the famous explorer, passed through Osa during his second expedition to Kamchatka.
The wooden forts were common for the region through 16th - 18th centuries.'