What is chantha?

Some articles on chantha:

Kattoor, Thrissur - Kattoor Angady
... Kattoor Angady has a "Chantha" (Commodity Exchange) ... Due to these reasons Kattor "Chantha" was Popular for exotic commodities comes from far distance ... Merchants and farmers from nearby villages used to come to Kattoor "Chantha" to buy and sell goods and produces ...