Previously you needed to visit all of the PPT(a-d) caches, collect the puzzle pieces, solve the Pokémon Puzzle Trail and Return to Pallet Town.
PPT(d) was archived in 2012 so the puzzle pieces are now attached as an image to this cache - although there has always been another way for the astute cacher to locate the cache...
The cache is not at the posted location (which would put you in the middle of the lake!).
The cache is located at: S35 ab E149 cd
The cache is an ammo box hidden in a tree and contains a variety of Pokémon toys. Alternative trades are accepted. No backtracking required if you are walking the loop (it is on your way back to the suggested parking coords at the start).