I've just placed a GeoCache/Letterbox hybrid in San Francisco

It's at 37.7877 N, 122.3869 W according to Mapquest
triangulation (I don't have one o' those fancy GPS toys, myself...)

Clues are in simple A-N substitution:

Gur ohvyqdat jurer gur crbcyr pbzr nad tb
Sebz Bnxynaq'f snve be fgbezl onaxf, nyfb

gb Fnhfnyvgb be Inyyrwb evqr
Jvgubig n pner sbe gessvp wnz ba gvqr

Vs sbie ol frira'f rira Fbhgu lbh'yy tyvqr
Gur cvref ol ahzore bqq gurl abegujneq evqr

N jbexvat cvre vf whfg gur guvat lbh frrx
Jvgu pbagenpgbef naq svfu naq n srj trrxf

Oruvaq svir lryybj cbfgf arkg gb n tngr
Lbh'yy svaq zr va n obk (orsber gur cnvag).

Have fun!
It's a urban haunt, in keeping with the best of both letterboxing
and geoCaching, there's a logbook, some silly stuff for
swapping, and a hand-carved stamp for logging your visit.

Not accessible at night when the pier is closed, and not advised
during late evening - this is the Big City down this end of things.
Early morning and noonish are lovely times for catching fishies...

Feedback on the relative ease or difficulty of finding this cache
(the box is in plain sight once you're there) is appreciated...
-Ruth