A little lower than the main observation deck you can go out onto the mountain itself. Some folks ski, some go for hikes on the glacier, others go on dogsled. And others, like me, spend a lot of time sucking in as much fresh air as possible. Not just because it smells like a nice winter day in Minnesota, but because the air is so thin up there you feel light headed and very sleepy.
Grindelwald was the perfect place to use as a base for our exploration, and the Derby Hotel was the perfect place to stay. Clean, comfy, really well located. The trains in and out of town stopped right below us (with minimum noise). Plus I thought it was great to sit on our balcony and watch people and trains.