A brief history of the map, from prehistoric cave paintings to modern maps of the world. People and places -Mapping - History of maps Learning Points Claudius Ptolemy's grid system allowed the curved surface of the Earth to be shown on a flat page. On the Mercator map, some countries appear much larger than they should. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.