The first location you want to explore when hunting for the best loot in Fortnite Battle Royale is the spot right above Wailing Wood at the G2 block of the map. There is a tall wooden tower with several floors. Some of the best chests you will ever see can be found here.
The first chest is hidden behind the wall on the second floor -- you'll see it glowing through the wooden planks. The other one is located at the very top of the tower with other random loot lying around it.
You will need to build an additional set of stairs to be able to get there, so have some wood material in your inventory before pillaging area.