What is the world's largest church building by area?
St. Paul's Cathedral in London
St. Peter's Basilica in Rome
Saint Isaac's Cathedral in St Petersburgh
Basilica of the National Shrine of Our Lady of Aparecida
St. Peter's Basilica (15,160m²), Basilica of the National Shrine of Our Lady of Aparecida (12.000m²), St. Paul (7,875m²), St. Isaac's Cathedral (7,000 m²)