The French National Institute of Geographic and Forest Information (IGN) is undertaking a groundbreaking project to create a nationwide 3D digital model of France using High-Density Lidar technology. This model will serve as the foundation for digital twins, enabling in-depth analysis of territories and the simulation of various natural and man-made phenomena. Unlike previous soil mapping techniques that relied on manual surveys or limited data from winter aerial photography, HD Lidar provides an extremely precise view of the land, with 10 data points per square meter. This allows for the creation of accurate digital surface models that can be used in numerous sectors, from urban planning and infrastructure to forestry, biodiversity conservation, and flood risk management. The data will be gradually made available as open data, fostering innovation through partnerships between public and private sectors, with the first phase of experiments and data utilization beginning in early 2022.