Text: The dominant feature of these ruins is the 45-m- (146-ft-) high, cylindrical Dhamekh Stupa, built in the fifth century a.d. , which is believed by many to mark the ancient site of Buddha's most famous sermon.
Entailment: Many people think the Dhamekh Stupa is built on the site where Buddha delivered his most famous sermon.
Contradiction: The Dhamekh Stupa is octagonal and 50 feet high.