Which collection of buildings is recognized as the "Historic Chicago Water Tower District"?

The "Historic Chicago Water Tower District" specifically refers to the collection of the Chicago Water Tower and Pumping Station. This area is significant due to its historical and architectural value, showcasing the Gothic Revival style. The Chicago Water Tower, built in 1869, is one of the few structures that survived the Great Chicago Fire of 1871 and has become an iconic symbol of the city. The nearby Pumping Station, built in 1867, was vital for the city's water supply system, illustrating the engineering advancements of that era. This combination of historic structures not only serves as an important reminder of Chicago's past but also highlights the city's architectural diversity, making it a focal point in discussions of Chicago's architectural heritage. Other options, while notable in their own right, do not carry the same recognition or historical significance in relation to the Water Tower District.