Starting at 10 a.m. a Civil War replica cannon will be on site at the Fort.
Every hour it will sound across the Penobscot River, but this weekend is the first of many exciting activities happening at the Fort.
"Every weekend there's a different event," Leon Seymour, of the Friends of Fort Knox, says. "On the Fourth of July we have a Elton John tribute band, that following Saturday we've got Scottish bagpipes, and then we have pirates sailing up into the area."
The cannon will be on site both Saturday and Sunday from 10:00 until 4:00.