Why not get yourselves on the Cape and head to the beach for the day? You can dress for the beach while you are in Boston. Pick up a few towels at one of the thousands of Job Lots on the Cape and have yourselves a Cape EsCape for the day. If you stay on route 28 around Hyannis you will see no end to miniature golf and ice cream places.

Have you thought about Plimoth Plantation?

If that's not of interest, I would go to Sandwich, then follow 6A out the north side of the Cape. It is lined with interesting things to do and sea and plenty of places to eat.

If they read Thornton W Burgess's books when they were little, his house is open as a tourist attraction. There is a water mill, shops, etc.

The real tat on rte 28 is in Yarmouth on the other side of Hyannis, if you want to play miniature golf and eat fried dough while looking at t-shirts.

All bets are off on a rainy day where nothing can move on the Cape. I would spend a rainy day in Boston and drive down later.

Where are you staying in Nantucket? We live there and might be able to help if you need it.

Sandwich offers much to see as mentioned. Heritage Museums and Gardens offers an antique auto museum, an antique carousel, toy soldier museum, changing exhibits, an antique windmill, and gardens for walking. Nearby you have the Sandwich Glass Museum and the Cape Cod Canal Museum.
Rent bikes near the Sandwich boardwalk at Ecotours.com. The boardwalk offers a good walk to the beach and dune area or you could bike the canal (7 miles each side) Two museums on the south side, Aptucxet Trading Post and Cape Cod Canal Museum.

I agree that the main stop between Boston and Hyannis is Plymouth. You can easily spend a few hours at Plimouth Plantation, then go down to the waterfront and see the Mayflower II and have a late lunch on the harbor.

http://www.plimoth.org/

Wonderful Plymouth and sandwich will be our stops. We are staying at chestnut house in Nantucket Abd then going to Wellfleet. Would love to hear about Nantucket and what to do during 3 days there. We will be renting bikes no car. Is it worth going to one of the preserves in the north and if yes which one.
Thanks again

The Chestnut House is right downtown, and you don't need to rent bikes unless you want to. You can get a bus to the beaches -- Jetties (sound side, gentle waves) or Surfside (ocean side, maybe an undertow, big waves) Both have toilets and beach food like hot dogs etc. Children's Beach is within easy walking distance and has a lot of kid-oriented events and more beach food.

I would recommend the Whaling Museum for kids the ages of yours because it explains Nantucket and the world of whaling, interestingly and it mostly is artifacts of daily life and not just pictures. There are films and a sperm whale skeleton and boats hanging from the ceiling.

Think about taking a cruise on the Endeavor, a Friendship sloop that will take you out into the Sound through the yachts and harbor points of interest, though I have to confess that Captain Jim is a friend of mine. People come back year after year for a sail with him, and w always go at least twice a summer. They dock on Straight Wharf, and you can book yourselves or have your guest house do it. You should reserve in advance because they are very popular.

Kids will enjoy eating on The Strip, a group of mostly take-out places on Steamboat Wharf. Most of them have food that is much better than their tacky appearance would suggest, and you can take the food to Children's Beach or along the waterfront on Easy Street. The Jamaican food at Stubby's and the fried seafood at the Easy Street Cafe (ask to eat upstairs) are both good, and the kids don't have to have Jamaican because Stubby's has a lot of variety. Famous for fries. The Juice Bar has great though very expensive ice cream cones. It is a madhouse in the evening, so go as a late afternoon treat, even if it spoils their dinner. They can always eat vegetables at home. If you want a "nice" dinner with some atmosphere, ask for a table in the basement at the Brotherhood of Thieves or maybe outside on their patio. The food is so-so and the upstairs dining areas are blah, but the burgers and curly fries are fine, and you can have a tuna burger without fear. But the basement atmosphere is great. Avoid Black-eyed Susans for breakfast, but it is fine for dinner.

That should get you started!

I would stop at Plymouth and at Plimouth Plantation with kids 9 and 11.

Plimouth Plantation is a great stop. If it is a good day for outdoors activities, there are also lots in Sandwich. (Get off the highway at the first exit after you come over the Sagamore Bridge, take a right at the lights at the end of the exit ramp, go under the bridge and you will be on 6A)

At the canal is a visitor center with lots of interesting info. You will have turned off 6A just beyond the town line and the brown sign for the canal on your left. At the corner of Freezer Rd. to the canal is the Shipwreck icecream place which also has hotdogs and burgers for lunch. Nearer the visitor center is Seafood Sam's (take out or eat in). A few non seafood items. At the visitor center there are picnic tables. Also picnic tables at the end of Freezer Road, where walking, bike road begins (also rest rooms).

On Tupper Rd. there is a stop and Shop where you can purchase cold drinks (in fridges next to check out), sandwiches and made up salads(near deli section), lobster rolls (down back next to fish section). Off course there are the usual grocery store selections of fruit and veggies as well.

Instead of taking the left for the canal, keep on rte 6A and a bike rental place will be on your right after you go up the hill. Twin Acres icecream (also hotdogs, burgers, grilled cheese, etc.) on your left.

Someone mentioned going to the Boardwalk beach (there is a non resident charge) and is apt to be full expecially if the tide is right.

All the things in Sandwich already mentioned are worth a stop as well--Heritage Plantation, Glass Museum, Dexter Gristmill, Thornton Brugess Museum and a pleasant litle town square.

On 6A as you leave town there is a lovely little miniature golf course on your left.

On Rte 6A a couple of miles outside of town on the right is Green Briar, the place that inspired Thornton Burgess's books. gift shop, walking trails, and quiet place to stop.

Just beyond the entrance to Green Briar (around the bend) is a cranberry bog. Nothing much to see this time of year as the berries are still ripening, but might be of interest to catch a glance as you pass if you have not seen one before.

A few miles farther on is Sandy Neck Beach. Parking fee, but generally plenty, rest rooms, snack bar.

6A is a peaceful drive and will take you to 132, the turn off for Hyannis. Be prepared for lots of traffic on this road. (132 is exit 6 if you go straight from rte 3 over the bridge to rte 6.)

On your way from Sandwich to Hyannis, some of the best old-school ice cream around is at the Four Seas in Centerville (and this in a part of the world where there is plenty to choose from!). Very popular, so expect a bit of a wait in line depending on the time of day/week...

thanks a lot folks!