When the boys light-heartedly assault La Rochelle, as an excuse for breaking their fast, they are in fact attacking the hilltop castle of Berlanga de Duero.
Before that they clumsily rescue Rochefort from the interior of the castle, where he is about to be clumsily executed.
Filming took place here in August 1973 and many local extras must have been used, judging by the number of Protestant rebels that counterattack the Musketeers from the castle.
The absence of sea at Berlanga was cunningly overcome by superimposing the waters around Dénia.
History student Roberto de Pablo showed us around the castle and the southern ramparts where the scenes of the Musketeers were shot.
Roberto’s father, Jesús, who runs the Hotel Villa de Berlanga, was one of the extras who earned 150 pesetas a day to counter-attack the Musketeers.