Over 200 million people live in Nigeria, which is almost twice as many people as the second-most populous African nation, Ethiopia. The world's only non-rectangular national flag is the flag of Nepal - it's shaped like two triangles in a stack. Although South American countries like Brazil and Colombia are leading coffee producers, the caffeinated bean originated in Africa. The world's largest cruise ship is Royal Caribbean's Symphony of the Seas. It's 1,188 feet long, which is about four times the height of the Statue of Liberty. The largest-capacity stadium in the world is the Rungrado 1st of May Stadium, located in Pyongyang, North Korea. About 114,000 people can sit in it. The oldest university in North America was founded in 1551. It's the National University of Mexico, founded by King Charles I of Spain.