Baseball / softball indoor batting cage. You'll need some artificial turf on the ground, a net, an L-Screen, a Jugs machine, and a few buckets of softballs and baseballs.

Inform local leagues of its availability, and rent it out by the hour.

If you set up a camera to monitor what is going on, and have a lock on the door with a passcode that you can change regularly if you want to, then you don't have to be there when people are using it. Just make some rules about leaving it in the same condition as how you found it, and you will have some good passive income.