Trummelbach Falls is 1.7 mi (2.7 km) from central Lauterbrunnen, why not stop by during your stay. Want to stretch your legs some more? Head to Staubbach Falls and Kleine Scheidegg, both nearby.
You can spend time browsing the exhibits at Valley Museum Lauterbrunnen in Lauterbrunnen. Amble around the area's lakeside or seek out the local tours.