Wellfleet's population of 2,500 increases to 17,000 during the summer as it is a popular vacationing spot. It is located in southeastern Massachusetts on Cape Cod, bordered by Truro on the north, the Atlantic Ocean on the east, Eastham on the south, and Cape Cod Bay on the west. Of Truro's 35.36 square miles, 61% is located inside the Cape Cod National Seashore.