Airborne lidar (light detection and ranging), which produces three-dimensional models of ground surfaces under the forest canopy, has become an important tool in archaeological research. On a microscale, lidar can lead to a new understanding of building shapes and orientations that were not recognized previously. On a medium scale, it can provide comprehensive views of settlements, cities, and polities and their relationships to the topography. It also facilitates studies of diverse land use practices, such as agricultural fields, roads, and canals. On a macroscale, lidar provides a means to comprehend broad spatial patterns beyond individual sites, including the implications of vacant spaces. A significant challenge for archaeologists is the integration of historical and temporal information in order to contextualize lidar data in the framework of landscape archaeology. In addition, a rapid increase in lidar data presents ethical issues, including the question of data ownership.