Lily Pad Ride

The Waterfall is a secret level, accessible only from the southwest island in Delfino Plaza, in the game Super Mario Sunshine. To get to it, Mario must ride Yoshi and jump on several boats to get to the island.

The access via pipe is blocked by a forcefield. In this secret area, Mario must cross through the poisonous river, collecting the Red Coins. If Mario were to land in the water, he will instantly lose a life. However, the lily pad that Mario is on will also disappear over time, making this quite a challenging level.

If Mario reaches the end of the area, but fails to get all eight Red Coins, he can walk on the sides to get back to the starting point to try riding the lily pad again. But because those paths are quite narrow, the player needs to move cautiously to avoid falling into either the poisonous water, or the bottomless gap.

There's also a pipe that takes Mario back to Delfino Plaza, but the player will have to repeat the steps taken to get to the Waterfall all over again.