Banana Farm

The Banana Farm is the only tower that has nothing to do with popping Bloons. This tower made its debut in BTD4, and gives income every round. The Banana Farm itself only gives 100 extra money per round, but when you upgrade it to More Bananas, you get 150 instead. It then upgrades to Banana Plantation, which gives you 250 money, but then the Banana Republic comes up. That gives you 500. Then the Banana Research Facility pops up, which gives you2000 money per turn.

Nice, huh?