What do you like to do? Will you be renting a car? Some cities have attractions that are easy to walk to and others are further out and might need to use some type of transportation. We don’t have kids but try to go on some type of vacation every summer. Usually in the US but have done some international and cruises. One thing to keep in mind is some attractions in different cities you have to book timed tickets for in advance and hotels might already be booked up for summer. Last year we went to Atlanta as we did not want to be on too long of a flight. They have Atlanta Braves, World of Coca Cola, Georgia Aquarium, zoo, College Football Hall of Fame, various museums, botanical gardens, CNN, and a big wheel among other things. About a half hour away is Stone Mountain. We live in the Baltimore area and are about an hour from DC. Baltimore has the Inner Harbor with the National Aquarium, paddle boats, science center, and different ships to explore. Close by is Oriole Park at Camden Yards where the Baltimore Orioles play, zoo, Fort McHenry where our National Anthem was written. art museums, and the Visionary Art Museum. For DC most of the Smithsonian museums are free but Air and Space is undergoing a renovation and requires a reservation as does the Holocaust Museum and African American Museum. We really like Museum of American History and Museum of the American Indian. We think the latter has the best food court. The National Zoo is free but you pay for parking and need a reservation. You also need a reservation for the Washington Monument. There are also various memorials. The National Archives am not sure if you need a timed ticket or not have not been in a while. The paid museums are The Spy Museum and Museum of the Bible. There is also baseball at Nationals Park. There is another branch of the Air and Space Museum near Dulles Airport called Udvar Hazy that has one of the actual space shuttles along with models of planes and other vehicles. It also has a tower you go up where you can see takeoffs and landings and hear communication with pilots. Also has an IMAX. Another attraction in Virginia not far from there is Mount Vernon the home of George Washington. There is a house and grounds to tour. A city that has a lot of attractions mostly within easy walking distance depending on where you stay is Philadelphia and also New Orleans. Good luck and happy planning!