From the Super Mario Wiki
Bowser's Seizures Palace Hotel.
Bowser's Seizures Palace Hotel is a hotel in the game Hotel Mario. It is the seventh and final hotel that Mario and Luigi must visit to rescue Princess Toadstool. At the end, they must fight and defeat Iggy Koopa in a Bowser costume and then Bowser himself as the final challenge of the game. In the ending sequence, the hotel is shown to crumble apart and collapse onto the ground as Mario, Luigi and the princess escape. This hotel also appears to be the only hotel to not have the lifts switch directions.