There are only four churches bigger than it in the world - St. Peter’s Basilica in Rome, the Basilica of Our Lady of Aparecida in Brazil, Cathedral of St. John the Divine in New York and Seville’s Cathedral. The Milan Cathedral is older than all of those churches, something which makes its size all the more impressive. It covers over 100,000 square feet and an entire city block. It's 354 feet tall, and can fit 40,000 people.