Small cache; but big enough to hold a few trinkets and the log book Some stealth is required. There are many caches in service areas along the 401. A complete list can be found here. .
When replacing this cache, please use only the actual feature holding the cache, not the neighbouring ones. This avoids making it too visible. This may sound cryptic but will be clear once you've found it.
Also check out Adventure Lab "A Trip Eastbound on the 401", Morrisburg ONroute