From Alpnachstad leads the worlds steepest (48%) rack railway up to Pilatus. From up there the view is terrific! You can see many lakes and far into Switzerlands countryside.
An insider tip is the café on the bottom of the railway, they have one of the best ice creams I’ve ever had. (with real vanilla and the strawberry one had fruit pieces in it!)
And of course the weather up there is colder than the heat in the city. Just don’t forget sun-protection (caring advice from a nurse).