Database containing observations of organisms at all taxonomic levels and within all taxonomic kingdoms mainly from Denmark. New observations are continuously added through the registration portal https://arter.dk. The portal is a collaboration project between the Danish Environmental Protection Agency, the Natural History Museum of Denmark and the Natural History Museum Aarhus. The project received generous financial support from Aage V. Jensen Naturfond and 15. Juni Fonden as well as an early contribution from the Danish state. The aim of Arter is to gather all available information about observations of Danish biodiversity and make the data available to the general public. Futhermore the portal offers free access to knowledge about the Danish biodiversity on species level making it easier for the general public to obtain knowledge about the species and protect same. The portal contains old finds as well as new ones and the users continously contribute to the overview of Danish biodiversity by reporting their finds directly into Arter.