I’m sure from what I have seen of Tom he would have attempted to deceive people from a young age. So the Coords don’t take you directly to the Cache but close, so you need to solve the riddle to find GZ. This is a busy muggle area only opened up a short while ago. There is a seat nearby to sign the log but you will be well out of sight when you find the cache at this time of the year but not so much in the winter. Cover the cache well.

Tom's Riddle

As I was going to St. Ives I met a man with seven wives.

Each wife had seven sacks,

each sack had seven cats,

each cat had seven kitens.

Kitens, cats, sacks, wives, how many were going to St Ives?

Multiple the answer by 20, now add this to the South and East coords.