The island of Bornholm, located in the Baltic Sea, has undergone a strong landscape change over the last 250 years, which has had an impact on the landscape form and functions (agriculture, recreation, biodiversity). In this paper, Hammer's historical map series from the 1750s is processed and evaluated using GIS technology. The results are presented and mapped according to the individual land use types and cultural landscape elements. For example, 250 years ago there was a very large proportion of extensively used heathland and very little forest, which is exactly the opposite today. In addition, there were a large number of smaller landscape elements, which together made for a diversely structured, agriculturally used landscape. This also includes the many smaller standing waters as well as wetlands and bogs. The large number of defensive installations recorded, such as redoubts, batteries, forts and signal points, clearly shows the military importance of the map and the significance of such installations for the security of the island at that time. The high number of windmills and water mills, the agricultural farms and the churches were also recorded. The resulting maps, which are also available digitally and interactively to the public, show the significant landscape change, which is placed in a historical context and discussed with its current effects, e.g. on biodiversity.