Making friends in college?

Im halfway through my bachelors degree and have yet to make a friend in college. I make friends in classes, but they always just stay in that class and we dont talk any other times. How can I make more friends outside of class. Im starting to feel a little lonely because I only have one friend and shes not even that great. I have a boyfriend but I believe you need more than just one person in your life. I need friends. Does anyone have advice to make lasting friendships outside of classes?