European destination 10 day’s end of May?

[Demings]

I am taking our daughter to Europe for graduation at the end of May for 10 days. Originally we were thinking Rome, Florence and Venice. However, I am now reading crowds can be overwhelming at this time. Any destination suggestions? We love food and architecture, I have been also checking on travelsites https://travelsites.com/ to get more about Europe but your suggestion also be helpful to me as europe is my first time journey