This paper provides an overview of recent research on patterned ground, a form of self-organization displayed in water-laden soils which are subject to diurnal or seasonal refreezing. Patterned ground of this type is found throughout the world in regions which have been subject to cold climates. The patterns can assume the form of polygons, stripes, and circles whose form is distinguished by variations in composition, color, or topography. The emphasis in this paper is on describing various forms of patterned ground and on elucidating the physics underlying its initiation and geometry insofar as they can be described by the free convection model developed by the author and his coworkers.