Tilings with translational symmetry in two independent directions can be categorized by wallpaper groups, of which 17 exist. It has been claimed that all seventeen of these groups are represented in the Alhambra palace in Granada, Spain. Although this is disputed, the variety and sophistication of the Alhambra tilings have interested modern researchers. Of the three regular tilings two are in the p6m wallpaper group and one is in p4m. Tilings in 2-D with translational symmetry in just one direction may be categorized by the seven frieze groups describing the possible frieze patterns. Orbifold notation can be used to describe wallpaper groups of the Euclidean plane.