This jumps straight in with the party travelling through the Untamed Gauntlet on other business, when the stream they are following abruptly ends in a cliff with a waterfall. It's too steep and slippery to climb up, the obvious route up is through an opening beside the waterfall.
There's a top-down view, a plan of the pathway through the cliff, and descriptions of the five chambers therein. To enter, the party needs to solve a puzzle: instructions for the die rolls required to solve it are given, but there's no actual puzzle given. Personally I prefer to let the party at the puzzle, and suggest die rolls if they get nowhere with it. Once they get in, there's a long spiral staircase going up (and down, but that's another story) which will let them get to the top of the cliff, provided they get past the monsters and other hazards.
Once they reach the top, they've actually come out at the top of a rocky peak even higher than the cliff. Here there's a cunning device that you can use to provide a hook into further adventures, a vision that gives them some inkling as to what is in store...
This is a rather thin 'something to happen along the way' which rather leaves you wondering why. Quite nice if you struggle to find ways to make wilderness travel interesting apart from reaching for the wandering monsters table. It could possibly be strung out into a complete session (2-3 hours) but that would be a bit of a struggle.