The East Crater
The East Crater is a location found in Wario Land 3. It isn't accessible from the beginning, however, when Wario gets the Crater Map from Tower of Revival, he can access this level.
The level takes place inside a volcano. To get to its bottom, Wario has to break several enemy blocks with barrels. Lumpies can also be found here. Wario can shake the ground to get them out of the way. In the bottom of this level, Wario can also find lava, that, if he falls in it, he'll turn into Flaming Wario. This will allow him to defeat the Lumpies. This is where Wario gets his very last power-up. This level is one of the two levels that have flames blocking Wario's way to other treasures, Wario needs the Fire Drencher found in Above the Clouds to pull them out. The other level is The West Crater.
A secret warp can also be accessed using the Pick-Axe from Above the Clouds. The Axe will make a fissure in the wall and reveals the warp. The level also has a wind cave. There is no air at the entrance at the beginning. However, After Wario finds the Jackhammer from Above the Clouds, it'll drill some holes and hot air will come out.
Treasuries
Gray Chest: Golden Gloves
To get this treasure, Wario must first get to the level's bottom by breaking enemy blocks with barrels and avoiding Jellybobs. Then, he has keep shaking the ground to make the Lumpy get to the top. He can use him to get the gray key. Then, Wario has to use the lava and transform into Flaming Wario, and defeat the Lumpies to the left who are blocking the way to the treasure chest. Then, he simply has to open the chest to discover his last power-up that allows him to lift heavy enemies.
Red Chest: Diamonds Crest
To get this treasure, Wario must first get the Fire Drencher from Above the Clouds. Then, Wario has to make his way to the bottom of the level and turn into Flaming Wario and defeat the Lumpy found on the right. Then, he has to process to the next room, where a Fire Snake can be found. Here, Wario must enter the first door he sees. Here, Wario must enter another door to find himself in an area with two Para-Gooms. He has to use one of them to get rid of the enemy blocks blocking the way to the Red Key in the first area.
Then, Wario has to come back to the first area and ground-pound a normal block to reach the key. the treasure chest is above him, however, enemy blocks and flame blocks are blocking the way to it. He has to return to where the Para-Gooms are and use one of them to break the row of the enemy blocks. Now, Wario has to let the Fire Snake turn him into Flaming Wario to break the flame blocks and reach the Red Chest.
Getting this treasure doesn't effect the Music Box World in any way.
Green Chest: Night Vision Scope
To get this treasure, Wario must first have the Jackhammer from Above the Clouds. Then, he has to break a row of three enemy blocks to the right to reach a new area. Here, Wario has to use the hot air to get to the upper area of this level. Then, Wario has to use his Bat Form to reach the Green Key. After turning back to normal, Wario has to go to the level's bottom avoid, the Kobats , and carefully make his way to the Green Chest.
This treasure reveals a secret door in Sea Turtle Rocks.
Blue Chest: Earthen Figure
To get this treasure, Wario has to get the Pick-Axe from Above the Clouds. Then, he has to go inside the warp created by the axe to reach a new room. Here, he has to pick a barrel, toss it above the floating blocks and catch it again and break enemy blocks. He has to keep doing this until he gets the Blue Key and reaches the Blue Chest.
This treasure doesn't effect the Music Box World in any way.
Reaction Abilities in this Level
Screenshots
The level's bottom. 
The wind cave. 
Another cave accessed using a warp.
