You'll probably spot Cartagena Cathedral from a distance before you actually find this important religious building. Look around inside if it's open or just appreciate the facade from the street.
If you're spending a while in Cartagena Walled City, Cartagena Cathedral is a fine place to kick off your sightseeing. This principal church is one of numerous attractions that'll keep you on the hop here. San Felipe de Barajas Castle, San Pedro Claver Church and Convent, and Jaime Moron Stadium are also waiting for you close by.