White sand and blue water views seal the deal
The Great Island Trail is actually a collection of named trails and use trails that can be combined to to create different options. The tread runs from hard pack ground to soft sand, giving the calves a workout. The soft sand is short lived.
Use the Great Island Trail along with the Tavern Trail to create a short historic loop past the Samuel Smith Tavern site. The Tavern was active from 1690 to 1740. It was excavated in 1969-70. Artifacts can be found in the nearby at the National Park Service Salt Pond Visitor Center. Nothing remains except a foundation. There is an information board showing some of the items found. Either use the beaches for this loop, or the trail up into the pines and oaks for some shade. Some of the best views on the hike are along the Wellfleet Bay Overlook.
For a longer loop include Great Beach Hill. There you can enjoy more shade, as well as some beach walking.
I did not try it myself, but the unmarked Great Beach Hill overlook, looks to add some scenic views of Cape Cod Bay.
Hiking to Jeremy Point, stretches this hike to it's southern most tip. Reaching this point is not possible during high tide, while staying dry.
Jeremy Point is a hangout for seals, as can be seen if you zoom in it via Satellite view. The numerous seals also attract Great White Sharks.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.