I detect old schools, especially the old one room 1800's schools. I have hit at least 3 of them recently. The first 2 were a bust, the one I'm currently hunting, has been my best site ever! As far as schools that are still active, I might try on a weekend, or during summer break.
Some of the finds from the 1879 school, over the last 2 weeks:
1848 Large Cent
1853, 1886 Seated Dimes
1896 Barber Quarter
2 V Nickels
2 Buffalo Nickels
1 no date Shield Nickel
about 20 Wheat Penny's
1915 Canadian Large Cent in same hole with old pcket knife
1 really rough Indian Head Penny
4-1940's Mercs.
1 decorative metal button.
I'll post pics on here when I am further along with hunting this spot.
Some other odds and ends too, but definetly recommend trying them!
It seems like everything in the older parts of Tampa are either fenced or posted. That's why I'm looking further afield out into the old farming towns.