The Dane Soren Poulsen spent the last 25 years of his life, from 1944 to 1969, building a world map 4.000 square meters (45×90 m.) at Lake Klejtrup in central Denmark.

It all started when she found a stone in the pond reminded him that the Mainland of Denmark. Inspired by this discovery, He returned the following year and placed stones on the Lake to create a world map with all continents. Today, This giant map has become a tourist attraction.