Trümmelbach Falls. This highly-touted waterfall has cut a gorge so narrow it actually appears to be falling inside the mountain. It’s in the bottom of the valley near Lauterbrunnen and it is powerful. It’s a busy tour-bus attraction, so expect crowds, but it’s also quite impressive. I usually recommend it as a rainy-day idea.
Trümmelbach Falls is a nice place to stop on a stroll along the Lauterbrunnen Valley. You can make it a part of a day trip from Wengen or Mürren, or pause there briefly on your way through the valley. An impressive feat of Swiss engineering, access to the falls is made possible through a series of staircases (plus an elevator) and pathways cut into the mountain gorge where the glacier-fed water pours through at as much as 20,000 liters per second. There’s an entrance fee to see the falls. Trummelbach falls also has an excellent cafe at the entrance.