Lake Constance (Bodensee)

Mist=must but I don't mind seeing some mists as well depending on the weather

I have never been there, but love what i have seen of Germany.
I should imagine walking would be on the menu. Get some good maps.

Not much help to you, but our son spent a year there as part of his university course. He loved it, and has been back several times. I will ask him about recommendations.

If you go to the Swiss side, a traditional food is Eglifisch.

Otherwise Mainau and Reichenau islands and if it's hot, enjoy a boat trip. Fascinating the prehistoric village at Unteruhldingen. Haveng been for about 20 years so am not sure what else.

Friedrichshafen is famous for blimps. I think there is a museum there.

Its on my list to visit. There are some lovely places in germany, which isnt really on the tourist map for the british which is a pity as the germans really like us so theres often a big welcome.

You don't say if you are staying on the German side or the Swiss one, but Konstanz itself is delightful. The museum at friedrichhaven could be good. But Mainau is my top tip - it never fails whatever time of year. Enjoy yourself!

Danke schon for all the above - I'm staying on the German side and feeling quite excited now.