I see you have a couple of days between Venice and Verona. I have always liked the Dolomites region. The mountains are gorgeous, and it´s different from the usual Italy. You could stay for a couple of days in the same place (Cortina, Alta Badia, Val Gardena, you name it) and do a bit of hiking. The hiking trails are well marked and many of them are easy, there are plenty of huts serving food, and so many flowers in the meadows...

On the 12th of May I see that you are thinking of going to Tivoli. Tivoli is quite easy to do by public transport, and much cheaper than the organized tours. We did it a couple of years ago. We asked the driver to tell us where to get off in order to visit first Villa Adriana (if you have read the Hadrian book by Marguerite Yourcenar, you will need to go there). It´s a really amazing place, and afterwards we got another bus to go up to Tivoli. We had lunch there, and visit the gardens. I still regret that there was a summer storm short after we finish the visit, and that we couldn´t walk around Tivoli, because it looks interesting. By the way, I had the worst coffee in my life at a cafe in the main square in Tivoli. Terrible.

Enjoy your holidays and your anniversary. Covadonga in Bilbao.