We've often wondered why cities are located where they are. It might make sense that Cleveland and Cincinnati grew up near a lake and a river respectively, but what about a land-locked town like Columbus? For those inquiring minds who have wondered about such matters, the Happy Dog tonight hosts a discussion that should answer your questions. At 7:30, Greggor Mattson, an urban sociology professor at Oberlin College, will be on hand to give a talk entitled "Why Cities Are Where They Are." It's part of the Happy Dog's new monthly lecture series, dubbed Happy Dog University. Admission is free. (Niesel)