Aren't lakes surrounded by mountains a common geographical phenomenon? Such as the Avalanche Lake... I believe that was a tourist spot once upon a time, known for its beauty. Lake Kawaguchi, Lake Biwa, Lake Chuzenji and Lake Tagokura are some examples in Japan alone.

[ Someone has been reading too much lately... she also had similar thoughts about the lake, but could only find similar other lakes instead of the lake itself. rip. ]

The closest result to "healing leaves" I've been able to gather were chamomile flowers which were once believed to be cure-alls... nothing about those leaves in the strange location, unfortunately.