The Banana Altar is located in a unique dead-end cave located in the North-Eastern-most mountain on the map (Section H2). It features a unique large Banana effigy and drawings on the walls of the cave.
Placing a banana on the offering plate in front of the Banana statue will cause bananas to fall from the ceiling in the cave and unseen Super Animals will begin to chant to a unique music track.
This will also unlock the Praise Banan Emote for the player that has placed the banana if they have not yet received it.
There is also a random chance that it will rain banans which causes every destructable or grass to have a chance of dropping banans instead of their normal drops.