Cam den Mail is a Letterbox Cache at the published coordinates.
To access this cache you need a four-digit unlock code. Look at the Property Sign opposite the entry to the park - it has five numbers. You need the final four, starting with a Zero.
This cache contains a logbook and stamp, as is traditional with Letterbox Hybrid caches. Please leave the stamp in the cache after you have used it to stamp your own letterbox logbook. Of course, you may sign or stamp the cache logbook without using the cache stamp.
The cache is placed on the owner's fence with his full support.