Here is my guide to a bunch of miscellaneous achievements early on in Bugsnax.
- Early on in the game, you'll find the mayor on the ground, and he'll give you a barrel to catch your first bugsnax.
- Catch the bugsnax, then turn around when facing the mayor. You should see a double waterfall.
- You can walk in the left side of the waterfall, by going through the water, for the achievement.