I did three runs in the four days that we were at the Cape. Each one took me along the Cape Cod Rail Trail (CCRT) that runs very near to the campsite we were staying at.
The section of the trail I ran (a little further for each run) is not particularly remarkable - being mostly through light woodland. It is however extremely user friendly - paved and vehicle free with good well-marked road crossings where necessary.
On the last day, my 11 mile run took me nearly 5 miles out along the trail and I finally got a view - not of the ocean but of the Namskaket creek in its rather attractive marshland.
and then I turned around and ran back again!