The fort was built on a hill, 60 yards west of the Allegheny River. The fort was in the form of a parallelogram, about 75 by . The curtain was made of hewed timber, stacked lengthwise. The four corners had bastions in the form of polygons. The bastions were built of saplings, eight inches (203 mm) thick, and in height. The gate fronted the river. Inside the fort were a magazine, several officer's barracks, with two stories and stone chimneys. The soldiers barracks consisted of 45 buildings outside the fort.