North Pole

The North Pole is a barren, icy region at the tops of both Mushroom World and Earth. It is believed that Santa Claus and his elves live there. Apparently, it was visited by Mario, Luigi, Princess Toadstool and Toad during the events of the episode "Koopa Klaus". They were originally not supposed to arrive there and were actually on their way to Hawaiiland when they suddenly ended up in the North Pole.