Fort Number 4

Charlestown, N.H. is still home to the spirit of the American Revolution with re-enactments (seen in the image below) and an open air museum that features a re-creation of the Fort at Number 4, which was a mid-18th century stockade fortification that protected Plantation Number 4, which was the northernmost English settlement along the Connecticut River until after the French and Indian War (seen in the back right hand corner).
While restoration of the site occurred in the 1960s, Fort Number 4 fell into disrepair following the Revolution, leading Pearson to see it in decay.

Image courtesy of https://www.crazycrow.com/site/event/return-to-number-4-revolutionary-war-weekend/.