Gotthard Train Model
Check out this great Märklin HO model train track layout of the Göschenen railway station at the entrance to the Gotthard tunnel.
The town of Interlaken
here is the train ride to the Jungfrau with very helpful explanations. Jungfrau Switzerland via Interlaken and Grindelwald.
Awesome Mountain Biking Trails
You can do mountain biking in Interlaken, yet, Interlaken is not the only attractive and challenging course in Switzerland for mountain bikers.