The setup was created for those who don't want to spend lots of time on building a defense system and its maintenance. I tried to use absolute bare minimum. (Edit added on 8/19/2022)
The setup only uses walls and tree seeds to create a barrier. It's cheap and requires very little maintenance. The only maintenance is fixing the walls. The construction only cost me 5 minutes.
The same setup will also work for the moon stone events.
Alternatively, you can plant marble trees.
