old style raised beds

more work than I want to do
but should be of help for someone

Any idea what the purpose is?  At first I thought the rocks were for thermal mass in cold climates.  But that thought quickly dwindled since it's the jungle.  Is it to keep pigs from rooting up the tubers?  Or keeping the plants higher and drier?

I'm speculating wildly, but watching the care with which he fitted his rocks together, it brought to mind the main reason I still used tall raised beds and containers, despite the extra problems this gives me with soil heating and drying in Oklahoma conditions.  Namely, small rodent-type chewing/digging critters.  It's not that they can't start from ground level and burrow under and up and in, but they don't, much.  Elevating the plants up and out of the critter normal zone of operations -- and depriving the critters of any easy access holes partway up -- seems to exclude them completely.  I think it's because they are heavily predated by flying things and thus prefer not to climb, but I'm just guessing.