Contaminated drinking water killed thousands of Chicago’s original citizens, so the city took the unprecedented step of digging a tunnel two miles long and 30 feet below lake bottom. Since the facilities on shore included an unsightly 138-foot vertical pipe, famed architect William Boyington concealed it with a limestone, castle-like tower that soon became a celebrated landmark. Through the first 150 years of its existence, Chicago’s iconic Water Tower has survived the Great Fire–the only public structure in the burn zone to do so–and at least four attempts at demolition. John Hogan pays tribute to the beloved monument that accompanied the evolution of Michigan Avenue from cowpath to Magnificent Mile.