In Mundaun, you play as a young man who has come back to his mountain hometown after his grandfather passed in a barn fire. However, you quickly find that things aren’t exactly as they seem. One of your first objectives after visiting your grandfather’s death site is to go to his grave.
Of course, this being a horror-puzzle game, you can’t just waltz into the graveyard and see your grandpa. Instead, you have to solve a few exploration puzzles to get inside. The first thing you need to do is get past the closed tunnel that’s keeping you from getting up the mountain.
The way we were able to get around the tunnel might not be intended, but it works. If you go behind your grandfather’s house and walk until you run into the mountains, you’ll find an area that you can climb up even though there’s no real path. You can see the exact area in the picture below.
Once you climb up, you’ll find yourself past the tunnel. On the cliff overlooking the graveyard, there’s a girl that you need to approach. She’ll toss a paper airplane toward the church by the graveyard. Then, you’ll need to get back down to the church and read the letter she tossed down.
This gives you a hint that opening the graveyard requires using the sun and the church to unlock a key. At first, this might seem a little confusing, but all you need to do is walk to the graveyard and look for a large rock covered in moss. Clearing the moss off of the rock reveals the key, and you’re finally into the graveyard. Once you visit your grandpa’s grave, you’re ready to continue your quest up the mountain.