Good friends of mine in their 50s and first time in Europe will arrive from Paris and spend 2 days in Switzerland on their way to Venice. Can somebody give me great tips on where to go in this area so they can have great time? Nature, things to see, views? Open to any suggestions.

Golden Round Trip in Luzern, departs from the bahnhof, you get to see the lake, go on a cog railway, go to the top of a Pilatus and a ride on the cable car, good for at least 1/2 a day, spend the rest going round the old town.

Thanks, that is nice, looking forward to hear more suggestions.

You can take a ferry by the Luzern lake and go to very interesting places, you should check that out.

There are lots of general suggestions for day trips here already.