In 1539 Sweden's last Catholic archbishop Olaus Magnus published in Venice a large map of Scandinavia called Carta Marina, after which this map served as a model for other map makers of the North. The Finnish peninsula and the gulfs of the Baltic Sea began to assume the right shape. Olaus Magnus was still poorly informed about the inner regions of the country. Only two lakes were located in Central Finland. LACVS PIENTE, the more southerly one, clearly refers to Päijänne, but the more northerly one, SVR PESI - HOLELA LACVS - is more mysterious. Erkki Fredrikson has interpreted that this twin lake (Suur Vesi and Hollolan järvi) also refers to Päijänne. Pictured in the map there are drawings depicting provinces and localities as if they were supplementary material. In the place of Central Finland there is a cowherd (PIET MADO) protecting cattle against snakes.