The Power Plant (also known as Metal Pipe World) is an area deep within the Dream World.
Features
The world has a scrolling background of grey pipes (leading to its latter name) with teal tiles and grey walls. There are also a lot of ":D" emoticons on the walls.
If you enter the world from Elvis Masada's Place, you will be in the restricted area as shown on the right. You can also enter the main world by going to the top of the pyramid in Sign World, then climbing down the pyramid and interacting with all the translucent balls you can find (when you interact with one, it becomes solid and starts rolling more quickly; the next ball appears only after the previous ball has been interacted with). Eventually, an already-solid ball with a red eye on it will appear (it's fairly easy to spot, as it moves erratically compared to the other balls). Interacting with this ball will transport you to the main entrance of the Power Plant. (Note: Once you access the main entrance of this area for the first time, an On-Off switch will appear in front of the pyramid in Sign World (it's set to "Off" by default). Turning it on will result in all of the balls re-appearing, including the red-eyed erratic one.)
The place where you enter has a window showing some of the moving balls you just touched. If you continue to go right, you will come to a pathway where there are a number of tanks containing different monsters. As you go down this pathway, it will get gradually darker, and you will then end up at some sort of cross roads. Step in the middle of the red circle and Urotsuki will fall down a hole into one of the tanks; pressing Z will trigger her to break out of it.
If you take the small path upwards that appears before the monster tank path, you'll eventually reach a short trail of White Fern World design that leads to the section of White Fern World that appears right before the area where the Tissue effect is located.