This is a video walkthrough for Natural Defense in the game Clash of Clans.
Use Wall Breakers on the wall where the Air Defense is located. Then deploy Barbarians to take it out and leave the rest of the job for a Balloon. Alternatively, just deploy Archers in the trees (yes, you can!) to take out the Air Defense, then deploy a single Balloon to mop-up, as above.
Loot: 20,000 Gold and 20,000 Elixir.
See other Clash of Clans single player walkthrough.