This manual is developed for the aerial photo interpretation work within the Swedish monitoring programme National Inventory of Landscapes in Sweden (NILS).NILS is a part of the national environmental monitoring activities of the Swedish Environmental Protection Agency (EPA) and includes all terrestrial environments – agricultural lands, wetlands, urban environments, forests, and coastal and alpine areas. Operationally, the programme is conducted by the Swedish University of Agricultural Sciences, Department of Forest Resource Management and Geomatics in Umeå.The manual is prepared as part of the methodology development work within NILS. In addition to the authors, some external reviewers have given their comments on the text and also contributed with material. Special thanks to Per-Anders Esseen, Anders Glimskär, Mats Högström, Per Löfgren, Ronny Löfstrand, Anki Weibull (all from the Swedish University of Agricultural Sciences), Margareta Ihse (Stockholm University) Ola Inghe (Swedish Environmental Protection Agency), Anneli Mattisson (County of Stockholm), and Sture Westerberg (County of Norrbotten). We would also like to thank Ylva melin and Heather Reese for the translation work to the English language.Following this introduction, the manual describes the NILS programme and outlines the structure of the inventory. This is followed by a detailed description of how the aerial photo interpretation is performed. Finally, instructions and definitions for the interpretation work are given. Some of the figures are mad in Swedish, but explanatory texts are given to the figures.