It’s been 28 years since Super Mario 64 launched but the previously unopenable door in Cool, Cool Mountain has finally been opened from the outside.
Discovered last month by Super Mario 64 speedrunner Alexpalix, who overcame the notoriously impassible door in Cool, Cool Mountain with the help of an extensive knowledge of Mario’s moveset and one furious mother penguin.
For the unfamiliar, the door in question appears at the end of the cottage slide in Super Mario 64’s fourth course, also known as Snow World. Upon reaching the end of the treacherous track, once infamously biffed by Dave Perry during a legendary moment on an episode of classic British gaming TV series Games Master, the door at the bottom of the mountain could open, allowing Mario to collect one of the sought after stars.
The door could only open outwards, and until last month, only hackers could hope to reenter the cottage via the same door. Nintendo have even made it visually obvious that the door was strictly a one-way only affair by removing the polygonal door knob from the outside. The geometry of the cottage, when viewed in a hack without textures, also reveals that the collision of the cottage prevents Mario from reaching the door and triggering its opening animation and warp sequence.
The excellent video below from Super Mario 64 video creator Pannenkoek2012 delves into great detail about why the door in Cool, Cool Mountain doesn’t open from the outside.
Mountain Mystery Solved
![Pannenkoek2012 demonstrates for the collision detection works with the Cool, Cool Mountain door and the mother penguin.](https://retrododo.com/wp-content/uploads/2024/05/cool-mountain-door-1160x653.png)
Curiosity is a trait present in many games. It’s what drives us to discover secret paths, hidden collectibles and stumble over random Easter Eggs in the name of fun. Of course, a door that previously opened but no longer could, is always going to spur a certain type of individual into action.
That’s where Alexpalix’s discovery comes in. The speedrunner discovered that by angering the nearby mother penguin and getting her to chase Mario to the cottage by picking up its baby, the mother penguins’ own collision data, when combined with a tactical backflip from Mario, the resulting glitch in collisions will send the plumber walking back through the Cool, Cool Mountain doorway.
Unfortunately, the discovery doesn’t aide speedrunners in their attempts to beat Super Mario 64 any faster as the maneuver takes longer to perform than just beating the cottage slide course normally, although it’s great to finally close the book on this mystery after almost three decades.