Super Animal Royale

You can find the Banan Cave on the top right corner of the map and the coordinates are G2. You're looking for a stone mountain with lots of trees on top of it and the entrance to the cave is on the left side and once you're inside break the boxes and head down the tight path and you'll find a banana statue with a brown plate / birds nest looking thing and you'll need to throw a banana directly onto the plate to unlock the achievement.

You can easily find a banana by going outside and cutting the grass with your melee weapon.

The Banan Cave is located at G2 on the map
The entrance is on the left side
Follow the path inside and to the back of the cave
Inside is the Banan altar
You have to find a banana on the map and bring it to this location then throw it on the offering plate at the altar

In video at 10:20

Achievement Walkthrough:

The Banan cave is located in the Northeast corner (G2) of the map near Thomas's Workshop. Before heading here, you'll need to find a banana. These are a grenade type that can be found on the ground, in boxes, in chests, and by cutting grass. Now head to the cave to find a banana statue with a plate in front of it. Throw a banana on the plate to make your offering.