The world of Teyvat is full of secrets, but occasionally you'll run into one that doesn't have a clear solution. You might need a certain elemental ability or better stats, or you're just not smart enough to figure out the puzzle. Whatever the reason, make use of the pins on your map to mark that location for later. You can also use these pins to mark the location of rare resources so you can venture back that way after they've had time to respawn. You can lay down up to 99 pins, so there's no reason not to use all of them.