Looking for recommendations for 4 nights in Europe to visit my son who is studying abroad in Madrid. Prefer to go to a city I haven’t been to or one that is easy with nonstop flights from IAD ideally. My son is 21 and we like to do activities rather the just eat and shop. I haven’t been to Switzerland so thinking 2 nights maybe in Interlaken (that’s where all of the activities are-skydiving and paragliding, etc) and 2 nights elsewhere. We are goodies and like nice hotel-but doesn’t have the be the best of the best as we will barely be in the room. We are flying in and out of Zurich. I just booked flights tonight (24 year old daughter coming too) and I can cancel if someone has a better idea. I also haven’t been to Venice but not much to do there. This would be for the first weekend in March. Too cold for Iceland. Already been to Barcelona, Madrid, Sevilla, Paris, London, Rome, Portugal, Prague, Morrocco, Amsterdam, he’s going to Dublin for St Pattys. Any suggestions would be great. He will have to fly from and to Madrid to meet us. I think Switz would be great. Just need a 4 night itin of lodging, dining (with 24 and 21 year olds), and activities. TIA