Awazon river basin

Awazon river basin is the main location in Virtual Boy Wario Land, however, only a little of it is actually seen since the game mainly takes place underneath it. Wario finds himself underneath the Awazon river basin after stumbling upon a trap door after following three Mask-Guys taking treasure behind a waterfall.

Virtual Boy Wario Land
Story from the instruction booklet ''I, Wario, have an interesting story to tell. One day during my vacation in the Awazon river basin, I landed my trusty seaplane, Bulldog, and decide to relax in the shadow of the beautiful Aldegara Waterfall. While basking in the sun, I spied some strange creatures with masks entering the waterfall. This piqued my interest! I hurried over and followed them into the waterfall. Behind the falls there was a large cave, and in the back of the cave … there was a vault filled with a glorious mountain of treasure!! Some of the masked creatures jumped me, but I quickly overcame them. "This treasure is all mine now!", I thought to myself and rushed in to collect the loot. Suddenly, the floor collapsed and I fell! I found myself deep within the Earth! I was quite angry and vowed revenge on these creatures, "I will get their treasure!!!"

Trivia

 * Its name refers to the Amazon River, but the M is flipped to a W similar to Wario's and Mario's names.