You don't have to be religious to appreciate the calming atmosphere of San Gil Cathedral. Check when the next mass is scheduled or when you can go for a wander through.
This San Gil principal church is a good place to begin your day of sightseeing. There's loads to enjoy nearby, like Parque Gallineral, Gallineral Natural Park, and Hill of the Cross. Take your time at San Gil Cathedral before making tracks to these other fine attractions.