Captain John Underhill's engraving The Pequot War 1637
Palisades are sharpened tree trunks used to surround and fortify an area against attach. The Eastern Native Americans used them to surround their settlements, and the Dutch used them to surround their forts. The Pequots, and related Algonkian tribes often had 2 hidden entrances to the village from the Palisade wall. Other tribes had only 1 entrance.
The sharpened tree trunk logs were placed vertically in a trench, and then the trench was filled. Horizontal supports tied everything together making a wall that was tight enough to prevent a man from walking through except at the entrances.