If you're visiting with kids or with any sports fans, Mus_e Olympique or the Olympics Museum should be on your list.
A museum dedicated to the Olympics and entirely to sports, graces the city of Lausanne. It includes a lot of interactive displays, games, interviews with legendary sports stars, medals, Olympic torches and more. Apart from the permanent exhibits, there are also some temporary ones. After you're done exploring, you can unwind at the little caf_ restaurant in the premises, which offers a stunning view of the lake.