Hi Girasoli,
For a day trip it shouldn't be too much of a problem to be in Lucerne on a Sunday - there's plenty you can do that isn't dependent on things being open.
Eg.
Walk across Chapel Bridge with its decorative paintings.
Visit the "Lion of Lucerne" monument - dedicated to the memory of the 700 Swiss Guards who were killed in Paris in 1972 - a very moving monument.
Walk along the ramparts of the city walls, built in 1386 - there are three towers open to the public (although probably not open on Sunday). The clock in the Zyt tower was built in 1535 and chimes 1 minute before all the other city clocks.
Take in the view up to the mountains.
And when you return for a longer visit, be sure to make the trip up Mt Pilatus - we did this via Lake Steamer across to the village of Alpnachstad and then rode a cog railway up the mountain (apparently the steepest in the world) to the peak of Pilatus (approx 2070 metres). We were greeted with a blanket of snow but clear views over Lucerne and over mountains. On the way down we travelled by gondola (interspersed with a toboggan ride half way day)and then a bus back into Lucerne - a great day out!
We enjoyed a great meal of rosti at Rutli on Rutligasse 4 (this was in 2007) - not sure about whether it is open Sundays. There are, however, definitely
some places open for meals on Sunday - haven't dined at this one, but at least you know you won't starve
Cheers
Christine
