Watched over by the Madonnina, the cathedral's high marble spires represent the city's most famous artistic and religious monument. The dimensions of Christendom's third-biggest church are still awe-inspiring, spanning 108 meters (354.3 feet) high and 158 meters (518.3 feet) long. A range of architectural styles feature the doorways of the 17th Century, the central balcony from the late 18th Century and the three main upper windows which are early 19th Century pieces by Carlo Amati. The Gothic cathedral's vast interior is grand with its impressive pillars, vaults, streamlined arches and wonderful statuary surrounding the nave. Light filters in through a crevice in the wall, positioning itself on the sundial that frames its main entrance. Gleaming statues carved out of Condoglian marble are perched atop its spires. Whether one is seeking religious fulfillment or is simply sightseeing, the Duomo leaves one spellbound.