Text: If not the most beautiful, the chateau is certainly the most formidable in the Loire Valley, a real defensive fortress, its black ramparts still forbidding despite having had their towers decapitated on the orders of Henri III.
Entailment: The chateau is a true defensive fortress, if not the most beautiful of it's kind.
Contradiction: The towers of the chateau were beloved by Henri III and are part of this aesthetically distasteful place.