Gosh, what an abundance of riches! An interesting museum (The Royal Armouries) in an even more interesting location (Fort Nelson) in a fascinating area (Portsdown) with absolutely stunning views.
Fort Nelson is one of a chain of forts that were built in the 1860s to defend the Portsmouth dockyard from a possible attack from inland. The perceived threat was from Napoleon III of France (who ironically died in exile at Chislehurst in Kent), and they became known as Palmerston's Follies as they were never needed for their original purpose.
The North Caponier
Or did they? Standing on the ramparts looking over the Weald, I couldn't help wondering if Palmerston and his chums were not more afraid of the ideas behind the French Revolution than of the French themselves. The forts are designed to be almost invisible from the north; the locals would know that they were there, but they wouldn't spoil the view from the surrounding manor houses and stately homes.
From the south, however, they are highly visible. Any French spy on board a boat in the Solent would have no difficulty spotting them. They would, however help to reassure the Portsmouth Navy personnel that they were protected from revolting English peasants.