The Cape Cod National Seashore Headquarters in Eastham Ma is a great place to stop by to discover naturalist activities offered by the Cape Cod Rangers.  Many guided hiking/walking tours educate the public on the geography & history of the Cape's seashore.  Guided tide pool programs also allow you to get involved, especially fun for children young and old.  Here's the link for the website....http://www.nps.gov/caco/