This amazing image, which turned up while I was searching for information about a completely different fort, inspired me to look up Fort Beauséjour and find out what and where it was.
It was a French fort in Canada, built in 1751-1754, during the period of tensions that led up to the Seven Years' War. It is located at Chignecto, the narrow isthmus that connects Nova Scotia to the Canadian mainland. The British had conquered Nova Scotia from the French in 1710, but the area still contained many French settlers, known as Acadians, some of whom were actively working to bring themselves back under French rule. A priest based at Chignecto, Abbé Le Loutre (you can see his church in the drawing above), was accused by the British of fomenting Acadian insurrection. So after the war broke out in earnest, one of the first moves by the British was to seize the Chignecto Isthmus and cut off communications between the Acadians in Nova Scotia and the rest of Canada.
Fort Beauséjour was besieged in 1755 by a force of New Englanders and British regulars under the command or Robert Monckton. It fell after three months, the first of the long series of British victories that ended with the complete conquest of Canada. (Fort Beauséjour is "D" on the map above).
I have noticed that period plans of star-shaped forts are very popular these days -- there are several blogs devoted to them, and I often see them on historical and art sites. This is Fort Cumberland, which the British built at Chignecto after they had control of Canada. Something about the fusion of beautiful geometry with deadly purpose makes these imagines highly attractive to many of us.