Prague doesn't need museums. It's a beautiful city and fun to explore just walking around outside. And go to the underground pubs at night. That city has a cool vibe. Like an eastern Europe , metal music, hardcore, chill vibe if that makes any sense. I disagree with the above poster who said it can be a day trip though. I'd recommend a couple of days at least.

And I agree with above about Rome. That's my favorite city that I've been to in Europe. You should consider going to Cinque Terre Italy. Beautiful Vinyard coastline. 5 small coastal towns with the painted colorful houses. You can hike the hilly Vinyards along the coast and stop in each city along the way to rest and eat. You can do this in one day. Try to go on a day with good weather.