It definitely is easier to travel with another adults – in such case, it doesn’t really matter if these adults are family members of friends. The most necessary issue is that they would most probably have similar interests and would like doing similar things while on the trip with you. You can be sure that in every European capital you will manage to find something nice to do for you as well as your friends. Nonetheless, the real challenge might be travelling with kids. They most presumably will not be interested in visiting too many museum or churches. You obviously have to pick up attractions for kids more carefully. And this text may be helpful – it shows 2 European capitals, which might be perfect to visit with your children.