If Jungfraujoch is for watching, First is for doing: Grindelwald's fun summit (2,168m) is a mountain playground — every activity optional, graded by courage. From the free Cliff Walk to Mountain Carts, standing Trottibikes, the four-line 80km/h First Flyer, and the eagle-style Glider. The Top of Adventure bundle beats buying separately, and the easy 50-minute walk to Bachalpsee delivers a Schreckhorn reflection rivaling Riffelsee with a fraction of the crowd.