This door was part of the Hoffmann Tower and Dam complex in Riverside, Illinois. The Desplaines River had been dammed at that location for commercial power back in the 19th Century. My fuzzy recollection is that the Tower (and the smaller building featuring this door) were part of an amusement park (Niagara Park) established by a brewer in the first years of the 20th Century. The park didn’t quite make it through Prohibition. Apparently getting high was an indispensable part of the amusement and the Tower alone did not suffice. Its other claim to fame was that it was among the earliest reinforced concrete structures in Illinois. I don’t know the function of the Tower or this smaller building. You will note, however, an interior door from the modern aluminium exterior door and the doorbell to the right. My visit there was back in 2006. Since then I understand the dam has been removed. You can find more info at the Library of Congress.