The Aayiram Kaal Mandapam ("Hall of a Thousand Pillars") is a separate hall in the north-east corner of the Meenakshi Temple complex, built around 1569 under the Nayak ruler Ariyanatha Mudaliar. The hall actually has 985 pillars; the missing pillars are an architectural illusion that lets each row look perfectly straight from the entrance.
The hall now houses the temple's small museum — bronzes, palanquins, processional vehicles, and a set of musical pillars that ring with different notes when struck (politely, for the children of the priests who demonstrate them). Allow half an hour.