Passage: The old town retains more than 50 historic monuments and 250 old houses, mostly dating from the 18th or the 19th centuries. Djuma Mosque, for instance, was established in the 10th century and rebuilt in 1788-89, although its celebrated hypostyle hall still retains 112 columns taken from ancient structures.

Question: How many historic monuments does the old town retain?
more than 50