Tree Bark to Find North
A good tip from Berndt Berglund's "Wilderness Survival." There are hundreds of ways of finding north but this is the first I'd heard of this method.
Tip 005 – Using a tree stump to find north.
“If you find a stump, it’s easy to tell north by looking at the annual growth rings. Annual rings are formed by living cells just inside the bark of a tree. These cells serve as a transportation system from the roots to all parts of the tree. To protect this delicate system, the tree protects the cells from the cooler northerly winds by growing a thicker layer of bark on north and north-east sides of the tree. These facts have been known by woodsmen in many parts of the world. A recent study by one of our leading universities proved this fact beyond doubt.”
This book was intended as a guide to North America so I'm not sure this counts for the rest of the world, but it's still interesting.