Underground Power Plant

The Underground Power Plant is a location beneath New Donk City in Super Mario Odyssey. During the story mission A Fresh Start for the City, Pauline tasks Mario with restoring the power here after getting the band together. To enter the Underground Power Plant, Mario must capture a manhole west of New Donk City Hall and move it to reveal the entrance. Prior to Pauline prompting Mario to restore the power, the manhole is blocked by a taxi.

Mario will emerge from a Warp Pipe upon entering. The generator Mario needs to activate can be seen through the glass. After going through another Warp Pipe, Mario will arrive in an area inhabited by Poison Piranha Plants and Urban Stingbies. There are large green platforms here that rotate when Cappy is thrown at them. Mario can use these to traverse the area without falling into the poison. While most of the platforms rotate horizontally, there is one at the end of the section that rotates vertically, which can be used to find a hidden Power Moon on a high ledge. Going through another Warp Pipe leads to the generator room, where Mario will encounter two Big Poison Piranha Plants. Defeating them spawns a Power Moon, which in turn unseals the switch that turns on the generator, allowing Mario to restore power to the city.

After completing the main story, there will be a plug and a large cubic battery in front of the generator. Mario can obtain a Power Moon by capturing the battery and inserting the plug into the battery's electrical outlet.

In the Nintendo Switch and Nintendo 3DS versions of Captain Toad: Treasure Tracker, a portion of the level Uptown, Downtown takes place in an area based on the Underground Power Plant. This area is inhabited by Piranha Creepers, and Captain Toad must pull on a switch similar to the power generator to restore power to various platforms throughout the level.