The cache is not, of course, at the location given. But it's
less than a mile from there. When you're at the cache, your GPSr
will tell you that the given location is some number of wavelengths
(call it P) of the hydrogen line (that's the frequency you get when
the proton and the electron change from being parallel to
antiparallel) away, on a bearing of 3.63 radians. Well, it won't
actually tell you that, but it'll tell you numbers that are
equivalent to that. P is the 939th prime.
But maybe the wavelength of the hydrogen line has temporarily
slipped your mind, so there's another way to find it. The title of
the cache should make it easier, you can ask a local for
directions. But locals probably won't have any idea where it is, I
know I wouldn't have until I set this cache. So there's a third
way. Look at the first picture, and a good map (or show the picture
to a local, we all know where it is).
That picture should make it easier. When you see this, you're
close to Chalk Dell.
That still gives you quite an area to search, so here's another
picture - when you see this, you're close to the cache.
Bring your own pencil

FTF honours go to the Bongtwashes