The California Institute of Technology is the top university in the world for the third time in a row. The science and engineering powerhouse based in Pasadena, Calif., was founded in 1891 as Throop University and renamed in 1921. The 124-acre campus is known for close student and faculty relationships, with a 3:1 student-to-faculty ratio. The school has also managed NASA's Jet Propulsion laboratory since 1958.