That place is heaven on earth. Hikes, hut hikes, gondola rides, picnics, waterfalls, alpine slides, etc. And if you have a way to leave kids and do some adventure….via ferrata in Murren is possibly the coolest thing I’ve ever done. There’s also hang gliding options around there as well.

Here's a good overview of Oeschinensee......it is unreal: https://fullsuitcase.com/oeschinen-lake-hike/