There are a lot of activities to do with your family. From Boston you can do trips only for one day like:
TRIPS FOR TWO OR MORE DAYS
Cape Cod is a beach located 2-3 hours from Boston where many people from the area go to spend the summer. I was there the last week of August. I found it a very nice place to go to relax and to enjoy with my son. We choosed a hotel in front of the beach called Sandbars Inn. The place was amazing. We did a bbq during the nigths in the sand just in front our room. Very very advisable.http://www.sandbars.com/
I haven’t been there but it seems it is special place to go for a rest and to explore the amazing beaches it has. More information here
Visit the website http://www.mvol.com for information about accomodation and how to arrive there. You should take a 30 min Ferry to arrive to the Island located south of Cape Cod. Some of the SF15 rent a big and pretty house with Airbnb for more than 10 people. This Island is famous to be the place where polititians spend their summer.
Storyland amusement park and White Mountains Reserve.
This park is located in Glen (New Hampshire), 2,30 hours driving from Boston. The park has a lot of things to do for clhildren of all ages. Just visit the website Story Land park and know more about the attractions. Also to have more information about the Ski Ressort visit http://visitwhitemountains.com/.
Indoor waterpark and Indoor ice arena. Golf. Riding
This amazing Resort is located 3,30 hours by car from Boston. You also can go to Vermont by train or by car.
Stowe. Ben & Jerry’s Factory, golf and balloon rides in summer. Skiing in winter.
This place is children friendly in summer and winter. Is 3.30 hours driving from Boston.
TRIPS FOR ONE DAY
Edaville park is located 1 hour driving from Boston. It is a nice place to spend with the family. There you can find the famous Thomas the tain and have a trip with it (the train is not exactly Thomas, you shoud know it) but the children are happy with that. For more information http://www.edaville.com/
Walden Pond. In summer is a good place to go for swimming. Water is not so cold.
The East Hill Farm.
Is a farm where you can stay for one or two ningths with your kids. Kids can milk the cows and play with nature and animals. Visit http://east-hill-farm.com/