Heck, I'll just take a temporary fence. Our HS field is the worst, where the OF slops down. My son hasn't given up too many hard hit balls, but 2 that he did ended up being HR because they ran down hill. One was a RF gapper from a righty that split the outfielders and ran into the softball field (2 outs in the 7th to spoil a shutout...ugh). The other a line drive that the LF took a step in, went over his head and rolled into the woods.
Worst part is, we're a pretty well to-do down with a very nice legion field, but HS team doesn't use it.