It's a looong way north from Boston/Cape Cod area, but here's the KT website: http://www.kingdomtrails.org/ Some think it's the best ST in the northeast.dfg70 said:
You should be able to find lots of fun closer though, in MA and southern NH.
Trail of Tears is a must if you're on the Cape looking for flowy ST. Also supposed to be some good ST in Plymouth, just off the cape up rt.3.
JZ