The title has nothing to do with the cache - although if you multiply it by 661 1/3 and visit the waypoint, you will be well on the way to solving the puzzle. All info from the obvious source.
You are looking for a container in a bag in the roots of a tree.
Got the information source ready? OK...
The cache is at
N51 (ACD + b.) . (TRTWP x Eton) + b.
W001 (NEF - BD) . (Room x b. x b.) + AF - Henley
You can check your answers for this puzzle on GeoChecker.com.
Onfr bs gerr ba onax, frr fcbvyre cvp.