The first St John the Baptist Church was built in the late 12th century when Cardiff had a population of less than 2,000 people. After being mostly destroyed in 1404, it took about 85 years to reconstruct. This makes it the second oldest medieval structure in Cardiff. The oldest is the castle across the street. The church was then expanded during the next 400 years. This Perpendicular Gothic clock tower crowned with pinnacles rises 130 feet. Inside is a carillon with ten bells.