Bastion, Octagonal fortress in Nanaimo, Canada.

The Nanaimo Bastion is an octagonal, three-story wooden blockhouse at 98 Front Street in Nanaimo, British Columbia. It was built with the pièce-sur-pièce method, in which horizontal timbers with tenons were fitted into vertical posts, requiring few nails. The squared logs were shaped with hand tools such as a crosscut saw, broadaxe, adze, auger, and pit saw. The structure sits on a masonry foundation.

The Hudson's Bay Company built this defensive structure between 1853 and 1855 to safeguard coal mining operations. It played a key role in protecting commercial interests during the region's early resource extraction period.

The Bastion's first floor was the office of Joseph William McKay, the Métis Hudson's Bay Company clerk who oversaw Nanaimo's mines and settlement. Exhibits there today cover the trade in coal that began after Snuneymuxw chief Che-wich-i-kcan showed black rocks to a Victoria blacksmith in 1849. The Nanaimo Museum also fires a cannon at noon in summer just outside.

The building operates as a visitor center and welcomes people who want to learn about local history. It sits in a central location in Nanaimo and can be viewed from the outside at any time.

This is the last freestanding tower that the Hudson's Bay Company ever built. It has been relocated twice since its initial construction, making its current location the final one.