According to the National Park Service, "In the northwest corner of Fort Vancouver's protective palisade wall, a three-story tower called a bastion or blockhouse rose above the surrounding plain. From the top, Hudson's Bay Company (HBC) employees could keep watch over the Columbia River valley and its gently rolling hills. The bastion was a common feature of HBC posts throughout North America. They typically had open slits or windows through which guns and cannons could be aimed at attacking enemies ... Though Fort Vancouver's bastion never saw any real military action it was still certainly an imposing structure. The tower, shaped like an octagon, was built into the northwest corner of the palisade. It stood three stories tall and was capped with a pointed roof. It was the tallest building at the fort. At the top level, eight three-pound iron guns pointed through small windows in each of the bastion's eight sides. When not in use, the windows were shuttered. The entrance on the ground level was probably on the bastion's southeast wall since that was the only side accessible from inside the fort. When the HBC left Fort Vancouver, the bastion fell into disrepair along with the rest of its buildings. Sometime after 1860, it burned to the ground. While it stood, however, the bastion was an important part of Fort Vancouver's image, and a key way that the HBC projected strength in a tangible, visible way."