Follow the path along the bottom of the crag. Once you arrive at
the location, you should find the 'whale's mouth'. The only way to
find the cache is to take the same Journey that Jonah did. It's not
as easy as it sounds to get swallowed though, and requires a degree
of 'intestinal fortitude', so care must be taken lest you are spat
out.
(This is a physically challenging cache. You
should only undertake it once you've done a little research and you
understand the risks involved (you should come with whatever
equipment you feel is appropriate, but it may be more hindrance
than help). The description and name should give you clues. I'd
strongly recommend against doing it alone.)
Many of the logs below give a lot of clues, so if you
want to experience the full challenge, don't read them until you've
completed it!