This embattled round tower is in the center of the Military District where Port Arthur’s commandant and officers lived. It is also situated on a hill overlooking the bay and prison yard. While standing on the inner walkway atop its lead roof, a sentry could vigilantly watch for suspicious activity. The cut-stone fortification was ordered by Commandant Charles O’Hara Booth and constructed in 1836 by teenage convicts from Point Puer Boy’s Prison. The Guard Tower was also used as an armory plus had three holding cells for soldiers and “free staff” who committed minor infractions.