After a spin by way of the monument’s history museum, climb the tower’s 116 steps to achieve the top. One of one of the best raw bars on the Cape is inside a no-frills, buoy-clad shack on the shores of Sesuit Harbor. Order oysters, steamers, and mussels from the bar, then grab a lobster roll — the kind Travel & Leasuire News that is lovingly placed in those red-and-white paper boats — from the principle restaurant. Enjoy it all at a picnic table overlooking Dennis’ Northside Marina on one aspect, and Cape Cod bay to the opposite. Opened in 2018,…