From the Super Mario Wiki, the Mario encyclopedia
The Nintendo Skyscraper is a huge building in the heart of Brooklyn. It only appeared in the Club Nintendo comic "Super Mario in Die Nacht des Grauens", and during the time of this story, Mario and Princess Peach live there together in an apartment. The Nintendo Skyscraper is also home to several other Nintendo characters, such as Link, Kirby, Diddy and Donkey Kong. Wario is the caretaker of the apartments.
In "Super Mario in Die Nacht des Grauens", a lightning strikes into the building and puts it into darkness. Mario walks down to the cellar in order to check the fuses. There he meets Kirby and Link, and together they notice that Wario is signing a contract with the demonic Abigor whose plan is to take over the apartments and let his diabolical fellows reside there. As a result, Mario and his friends have to fight against a bunch of monsters in order to save the residents of the skyscraper. They are able to do so with the help of a chest they find in the cellar. It contains clothing and weapons of Van Helsing which they make use of in their fight.