This chapter focuses on the functions of medieval geographical representations, in the form of both texts and maps. The concept of a spherical Earth is traditionally associated with the authority of the Pythagorean school around 500 B.C, but the first explicit proofs are laid out in Aristotle's De caelo. The study of geography in the Latin West differed from that in the Islamic world in one important respect: that the West did not have ready access to Ptolemy's Geography until the beginning of the fifteenth century. On a different scale, and adhering to a different geographical tradition than that of the scholarly worldview, was the medieval practice of describing land and property in a local setting. The medieval pilgrim or traveler usually found his way by asking directions. The world maps of Pietro Vesconte of the 1320s, the fascinating moralized maps of Opicinus de Canistris, and the Catalan Atlas were all mixtures of portolan charts and mappaemundi.