The Iberian Peninsula extends from the southernmost extremity at Punta de Tarifa to the northernmost extremity at Punta de Estaca de Bares over a distance between lines of latitude of about based on a degree length of per degree, and from the westernmost extremity at Cabo da Roca to the easternmost extremity at Cap de Creus over a distance between lines of longitude at 40° N latitude of about based on an estimated degree length of about for that latitude. The irregular, roughly octagonal shape of the peninsula contained within this spherical quadrangle was compared to an ox-hide by the geographer Strabo.