The Cache is not at the published Co-ords.
But this a lovely park near Paddington Station where you can see a Paddington Bear Statue, marvel at the new butterfly showpiece garden or sit at one of the many benches that are in here. There are cafes and pubs close by to get refreshments and the near by railway Station has 24/7 free public toilets.
This cache can be found once you have solved A Tour of Paddington Adventure Lab.
The Co-ords for the final will be revealed at the final location of this lab, that will need to be completed in the order set by the CO.
Start at Norfolk Place a short walk from here.