The San Diego Zoo is Celebrating its Centennial and for 100 years has been a world leader in animal conservancy. Dr. Harry Wegeforth founded the zoo after he discovered abandoned animals left over from the 1915 Panama-California Exposition World Fair. More than 3,700 animals from 650 species make up its expansive family. It was the first zoo in the world to recreate animal habitats instead of just house animals in cages which has led to the happiest animals. Orangutans, Pandas, Koalas & Elephants are among its most famous residents.