I am planning to hit Europe again with my adult sons (24 abd 27y) in 6/2025. I was thinking to fly to Vienna, and fly home from Prague. Where to go (1 more city?) in th midle - Munich perhaps? Other cities that I should consider, and not do Vienna and Prague?

I have been to Vienna 1x 30y ago, many other places as well. My sons have been to Germany, Italy, Ireland, France, Denmark, Sweden.

Any advice is appreciated!

Flying open jaws makes sense, but you don’t say how long your trip is. You will need 12 days for 3 cities, Munich should be at the start or end, not the middle, Budapest also makes a good trio with Prague and Vienna. But remember that you loose half a day each time you move cities.

I would ask your sons for their input too, what they want to see and do. And get started asap with hotels and air/train bookings, June is just round the corner!

Bratislava

As geetika says, it depends on how long you have. For my interests, I'd want 5 days in Vienna and 4 in Prague, so you might need more than that if you want to include any other city. And yes, do, please, get your sons involved in planning ... and do it SOON. It's late to plan a trip for June 2025.

Krakow is one of my favorite places in Europe. A 3-city tour of Vienna, Krakow, and Prague would be amazing.

However, cities are not the only places you can visit. If you take the train to Brno in between Vienna and Prague, from there you could visit and stay at the Mococha Abyss. This is a terrific area with hiking, caves, and a fantastic underground river. You take a cable car to get there, but in this case you take a cable car down into the gorge.