“Frank’s Fort” or “Frankfort Island” as known to Google Maps is now an island and is perhaps the first structure built in what is now Eliot Maine, located in Mast Cove close to the Eliot Boat Basin. During the 1630’s the land was still connected, steep but flat on top. Sea level rise and the fast moving waters of the Piscataqua erroded the land and it’s now an island. The island is now private property owned by James Austin of Kittery Point.
Built in the summer of 1631, Frank’s Fort, an ancient name, is named after Francis Williams, overseer of the Laconia Company. The company failed, but more about the Laconia Company can be read about here (coming soon). (3)
Franks Fort, and about one mile north “Watts Fort”, also called Darby’s Fort, which used to be another stop for the Laconia Company men traveling along the Piscataqua. They were never actually fortifications and no structures can be seen today. Watts Fort is completely under water. (3)
During the American Revolution, rebels attacked the British occupied Fort William and Mary at New Castle. They took firearms and gunpowder and burried the powder Franksfort Island. The cache was then distrubuted to the militia and which happened to be used at the battle of Bunker Hill in Boston.
I’ve also read that “in 1524, John Verrazani, an Italian navigator, in the employ of the French, or Franks, explored the Piscataqua ; and from this source came the name, Frank ‘s Fort” (19) although I do not believe this account at this time.