What does this look like?

So my mom's neighbor saw me metal detecting my mom's yard and asked if I would want to check her yard. I said of course thank you so I did some research and her house is only a 1950 but I found a old map of her property and can't tell what was there before. To me it looks like a church or a school any guesses? I hate old pics cause they are so blurry zoomed in. Today there is just a small house built right in front with a huge like football field size back yard where this building was. So what do you think it was? Maybe just a huge house but it just looks different to me.