One day, I saw the billboard for Blausee at the Solothurn station.
So my husband and I decided to go there spontaneously. Fortunately it was during the off-season so there were not so many people at the lake. Plus, it was a beautiful sunny day. The lake was literally blue and there were many trouts swimming and they seemed to be relaxed. Well, I am still hesitated to show the picture of the trout that I ate..but here it is. We also had a dessert. This was recommended by the gentleman working there.
Blausee Berner Oberland: http://www.blausee.ch/wb/pages/en/restaurants.php