Sometimes we go to Rosedale using the Princes Highway, other times on the inland route through Goulburn and down Clyde Mountain.
At the top of the mountain pass, there is a small cave which is known as Pooh's Corner. Apparently this cave was used as a munitions store during World War 2. The idea was it could be detonated to stop passage from the coast to Canberra, inland.
This site has further information, but I haven't managed to find any explanation as to when people began leaving bears there. Would love to hear from anyone who can shed any light.
Unfortunately, from time to time the cave is vandalised or burnt, but it is always restored in time....so someone "tends" it!