A view of the keyhole from above. There is the option of rappelling over the top of the chockstone but this would result in a free-hanging rappel down a very narrow chimney. The best option is probably just to rap through the keyhole, although this would be more difficult with a pack on. You may have to lower your pack through first then put it on. Or, better yet, don't even take your pack with you up the chimney. September 9, 2007.