Holy Cross (Coonan Kurisu) Church marks one of the key moments in the history of Kerala's Saint Thomas Christians. In the 17th century, local Christians gathered here in protest against Portuguese Jesuit control, an event remembered as the Coonan Cross Oath.
The church is a small stop, but it adds useful context to Mattancherry's layered religious history, especially if you are also visiting the Paradesi Synagogue and Mattancherry Palace nearby.