The given coordinates do not point to the cache. They point to the parking area.
To find the N and E coordinates for the cache you must visit two separate locations.
1)N58 57.293 E5 43.215 You'll find the E coordinate as a white label behind some signs.
2)N58 57.175 E5 42.862 You'll find the N coordinate as a black label behind a sign.
The coordinates are not hidden in a box, just written down at the given locations.
You now have the coordinates for the cache. You are approxemately half the way around the lake when you find the cache, so I will recommend you to continue all the way around.
The cache is a black film canister with log. Bring your own pen!! Stealth required!! Make sure to put the cache back on the same place, and that it is securely attached.
No trade objects! You will understand when you find the cache.