Officially recognised in the Guinness Book of World Records in 2013 as the biggest school in the world, the City Montessori School in India was founded in 1959. Notably inspired by the teachings of Mahatma Gandhi, today the school has more than 55,000 pupils! That’s a lot of desks... The school has 1,150 classrooms in total across 17 different campuses. “Oh no, I left my exercise book in room A1058! .