at the old West Side Park in Chicago there was a mental hospital in back of left
field.

This reminds me of the mental hospital where the movie version of One Flew Over the Cuckoo's Nest was filmed. It is in Salem, Oregon, and is situated well off the street in front of it, having a very large lawn area between the street and the building. So, it is appropriate here in Oregon to say that the mental hospital is a good bit off Center (street).