After Vauban'became superintendent of fortifications, he visited Le Château and drew up a proposal for enclosing the town (with arrow-headed bastions, according to his first system) as well as replacing the citadel's second enceinte (which was of dubious value) with a hornwork. He then made a second proposal for the town's fortifications using the tower bastions'and counterguards'of his 'second system'. Work began in 1691, but progressed sporadically before being terminated in 1714, leaving the town's defences without any outworks. One of the detached bastions was made as an earth-work, but was never revetted - this can be seen on the relief map.
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