The Bare Earth: A Lidar Map of the World, Joining Fifteen National Lidar Surveys to a Global Shaded Relief

I join fifteen national lidar shaded relief services into one zoomable web map of the world: England, Flanders, the Netherlands, France, North Rhine-Westphalia, Bavaria, Czechia, Austria, Switzerland, Slovenia, Luxembourg, Spain, Norway, Japan and the United States. Each is loaded live from the publishing agency's own open web map service and drawn over a global shaded relief, so the national survey takes over wherever one exists. A gallery of 23 places shows what bare-earth lidar reveals beneath trees, crops and buildings: Iron Age hillforts and oppida, Neolithic flint mines, a deserted medieval village, the craters of Messines, Vimy and Verdun, a Roman gold mine, burial mounds in Norway, Japan and North America, karst, and three landslides. The paper documents each service, its resolution and licence, explains why some countries with open lidar cannot be shown, and gives each gallery place a short sourced note. Interactive map: https://maps.tristanhotham.com/lidar-world/. Code: https://github.com/Tristan-Hotham/lidar-world. Blog post: https://blog.tristanhotham.com/2026/10/31/lidar-world/.