In an era before cell phones there used to be scattered throughout the city pay phones of many types. If you are old enough to remember then you have seen the old phone booths, perhaps on the corner of two intersecting streets, or a phone booth in the local drugstore where back in the 50's & 60's they also had a soda fountain where you could get a green river or a black cow.
This cache illustrates another pay phone type. Phone from your car, where you drive up and park next to the phone to make your call. The phone here is long gone but you can envision yourself pulling up to this spot, taking the phone off the reciever, reaching out and inserting your dime, then pushing the buttons to make your call. So, who are you gonna call? Not Ghostbusters, they were't around. Phone Home.