Tobogganing Park in Leysin is a must during the winter season. It is the biggest snowtubing park in Switzerland!. There are special slopes for all ages and crazy rides for the thrill-seekers, like the 360 looping or the big air bag (need to pay extra for the latter). In most of the rides you can go 2,3 or 4 people attached making it more fun. And for the little ones (until 5 years old), there are also some easy, fun slopes. I strongly recommend to call before to check on the snow & weather conditions and also to reserve your tickets.
https://goo.gl/maps/NpwaJNhsSSgEDizm6
https://www.aigle-leysin-lesmosses.ch/en/P492/tobogganing-park