A Boulder is a reoccurring object that appears in the series. They made their debut in Super Mario World as an obstacle.
Boulders reappear has help objects in this game. Only Chunky Kong can lift the boulders in this game. Boulders usually block Music Pads that usually lead to Golden Bananas (they're mainly found on DK Isles). In some cases, boulders can also be used to keep switches pressed down.
In Mario Kart 8, the Boulders were obstacles in the game for Bowser's Castle.