>> Lucerne becomes our base town. Now please help us plan a 6 days itinerary. I see a lot of choices like Zurich, Lucerne itself, Interlaken, Mt. Titlis, St. Moritz, Murren etc. Keeping our 2 little kids in mind, how best can plan in order to cover most top attractions without being exhausted?
>> 2 kids ages 8 & 5
The key here is to keep travel times within reason. Any plans you make should be checked in the Swiss Timetable so you know how long it will take to get there:
That rules out St Moritz, which is on the other side of the country, and takes a minimum of 4 to 4.5 hours of travel each way.
Interlaken itself is not worth a visit, but Mürren is. Travelling from Luzern to Mürren will take the best part of three hours each way. You'll have to consider whether that is too much for your children.
Zürich has a nice old town for walking, and you can go for a cruise on the lake, but Luzern is better for both activities.
Titlis is near Luzern, as are a lot of other attractions, so I would concentrate on those, by using the link to Luzern that Annika has already provided you. Examples of activities and excursions include mountain trips to Titlis, Pilatus and the Rigi, boat trips on the lake, the Swiss Museum of Transport, Lion Monument, walking through the old town and over the Chapel Bridge.
Lots of mountains have playgrounds. Some examples you might want to research for suitability include those at the links below.
www.rigi.ch/en/Experie nce-Enjoy/Summer/Families/ Playgrounds
www.pilatus.ch/en/pila tus-active/summer/families -children/