On a ridge above Sabino Canyon there is a small stone structure - the structure isn't noted on the topo maps I have and you won't find any informational signs as you circle the structure, but a 2012 article by Doug Kreutz for the Arizona Daily Star explains that "The structure is a water tower - or above-ground storage facility - probably associated with a well to the south and east" and likely built in the 1930s or 1940s.