No portion of the Gettysburg battlefield was occupied longer than the campus of the Lutheran Seminary, serving one army or the other for all three days of the battle and beyond. Though it operated as an observation post, hospital, headquarters, rallying point, and fighting ground, perhaps no aspect of the landscape has remained as quietly influential as its use as a heavily concentrated artillery platform. During this tour, we will focus on more than 20 United States cannon that occupied the campus on July 1, the 18 Confederate cannon that took their place on July 2 and 3, and the stories of the artillerists who manned these guns.