Text: They were built at the very beginning of the 16th century by Sultan al-Ghuri, the last Mameluke ruler, and his mausoleum at the heart of the development is now a cultural center hosting regular performances of the Whirling Dervishes (who achieve religious ecstasy by circling around in continuous motion).
Entailment: The Whirling Dervishes regularly perform in the mausoleum of Sultan al-Ghuri.
Contradiction: THey were built in the 18th century.