After you leave Scargo Pottery you could travel to Scargo Tower in Dennis on Scargo Hill Road . Maybe not so good on a rainy day but great on a clear day or at sunset.
http://www.dennishistsoc.org/historical/scargotower.htm

The Cape Cod Playhouse in Dennis on Rt 6A they have a children's theater. http://capeplayhouse.com/

Any age would enjoy Michael Magyar's glass blowing workshop just east of Sandwich on 6A.

Harwich Junior Theatre in West Harwich ...

Programs for children of all ages at the Cape Cod National Seashore (U.S. National Park Service) Cape Cod National Seashore 99 Marconi Site Road Wellfleet, MA 02667. www.nps.gov/caco

Cape Cod Rep Theatre .. lots of shows/programs for children ..
1772 Main St. Route 6A in Brewster www.caperep.org

The Playhouse in Dennis offers wonderful children's theatre and musicals during the summer season ..

Musuem of Natural History (They do offer special programs for children during the summer).

From Saquatucket Harbor in Harwich .. take a high speed ferry to Nantucket for the day ...

For a fun lunch with children .. Sesuit Harbor Cafe .. right on the beach .. in East Dennis

Families also enjoy in the Dennis area ..
Scargo Lake
Corporation Beach
Princess Beach - Dennis

Ice cream ...
Sundae School - West Dennis
Captain Frosty's - Dennis

Kayak Rental on Rt. 28 in Dennisport (508) 398-0080). You can rent manually powered and electric paddleboats, canoes, and kayaks ..
www.insidecapecod.com

Lots of mini golf .. go Karts ..

Libraries offer much for children to do .. be sure to visit the local Chamber and buy the local newspapers .. Look at the Calendar Section ..

Take one of the many cruises offered .. Bass River Cruise ... is only one ..

The Cape is a great place for all ages .. Enjoy the visit .. !

Another option in Mashpee ..they offer different programs year round ..
Cape Cod Children's Museum
www.capecodchildrensmuseum.org