1 St. Peter's Basilica, Vatican CitySt.Peter’s Basilica in Vatican City is the biggest cathedral in the world and is considered as the mother church of the Roman Catholic religion. The basilica stretches over 186 meters in length and has an internal area of 15160 square meters. The huge cathedral can accommodate 60 thousand prayers at a time, making it the biggest church in the world.
2 Basilica of Our Lady of Aparecida, BrazilThe basilica of our lady of Aparecida in Brazil is the second largest church in the world, after St. Peter's Basilica in Vatican City. The shrine, built between 1946-1980, has an internal area of 12000 square meters that can accommodate 70,000 worshipers. The dome of the cathedral is 70 m (230 ft) high and the tower reaches a height of 102 m (335 ft). It receives up to 10 million visits per year.