This letterbox hybrid cache is not at the posted coordinates, but this is a good place to park and start your adventure.
Boîte aux lettres is the French term for letterbox. Welcome to this new series of London Letterbox caches honouring many different countries and languages around the world. This cache contains a stamp that is not a trade item and should remain with the cache.
From the listed coordinates on the roadside, you will be hiking west into the woods. You can find the final cache coordinates by projecting a waypoint 27 m away, at 295 degrees true.