Fort Blunder: The Fort That America Accidentally Built in Canada -
- Engineers began construction of the fort in 1816. They placed Fort Montgomery on Island Point, a small promontory jutting out into the northernmost end of Lake Champlain. The fort, when finished, would be shaped like an octagon and have 30-foot tall stone walls deploying 125 cannons. No British warship could sail past it without coming under heavy fire.There was just one little problem with the fort. Due to a surveying error, it was accidentally built half a mile north of the Canadian border.