In complex analysis, a Riemann surface is a surface composed of copies of the complex plane. Since the features of the Earth's surface can be associated with the complex plane by stereo graphic projection, a layperson may prefer to envision a Riemann surface as a surface that has been seamlessly decorated with copies of the Earth's surface—what we'll call Weird Earths. Participants will fold their own Riemann surfaces from pre-cut and pre-creased cardboard strips. The maps printed on the strips are Oscar Sherman Adams' "World in a Square II."