The Super Mario series is known for its bizarre power-ups and Super Mario 64 is no exception with the addition of three colorful caps that allow Mario to reach all-new areas. Finding the winged-cap gives Mario flight and a see-through cap offers Mario the ability to walk through walls. All of these caps are hidden throughout the halls of Princess Peach's castle, but one such cap might have players scratching their heads searching for it. That's the Metal Cap.
The Metal Cap, unlike the other two is not found through the halls of the castle itself, but instead found within one of Super Mario 64's many levels. Once players have faced the initial battle with Bowser in the Dark World, they will be gifted a key to the castle's basement where they'll face further pitfalls and all new levels to collect more Power Stars. In the basement, down the halls and to the right of the painting holding Lethal Lava Land, is a star-laden door on top of a small ledge. In the room behind the door is a pool of metallic water with which holds Hazy Maze Cave, the sixth course in the game and the only means of unlocking the Metal Cap.
After earning enough Super Mario 64 stars to enter Hazy Maze Cave, players should dart to the left, making sure to long-jump over the gap into a room with a metal-grated floor and boulders falling in the distance. Navigate through the room, making sure to dodge boulders and avoiding falling into the deadly pit in the middle until you reach a metal door leading to a room with an orange and yellow elevator that will lead Mario to the very depths of Hazy Maze Cave.
In the depths, Super Mario 64 players will find a large pool of water with a dinosaur swimming in it. This is Dorothy and she's key to guiding players to the Metal Cap. Hop on Dorothy's back and do a ground pound on her to make her lower her head, which Mario can then hop on to control the friendly beast. Once on Dorothy's head simply face a direction to make her swim that way and start heading her towards the back of the room to the double-metal doors. Through these doors is another pool of metallic water that Mario must jump in to be teleported to the room carrying the Metal Cap switch.
Mario will instantly start with the cap already on and must navigate the swift waters to reach the green Metal Cap switch in the back of the room. Hop through the room's obstacles, making sure to avoid the annoying Sniffits until Mario can ground pound on the switch to unlock the Metal Cap in any levels in appears in further.
Super Mario 64 is currently available as a part of Super Mario 3D All-Stars on the Nintendo Switch