Naturalis Biodiversity Center, Leiden

Naturalis Biodiversity Center is a national museum of natural history and a research center on biodiversity in Leiden. The museum, except the research facilities, was closed from September 2018 to mid 2019 due to renovations. Temporary exhibitions were held in the Pesthuis (historical Plague hospital), the former entrance building, during the renovations.

Although its current name and organization are relatively recent, the history of Naturalis can be traced back to the early 1800s. Its collection includes approximately 37 million specimens, making it one of the largest natural history collections in the world.

The current museum is known for the numerous objects in its collections. Prior to the merger with the Zoölogisch Museum Amsterdam and National Herbarium of the Netherlands, there were approximately 10 million zoological and geological specimens in the Naturalis collection. Following the merger with the collections of the Zoölogisch Museum Amsterdam and National Herbarium of the Netherlands in 2010–12, there are now approximately 42 million specimens.

The largest part of the collections are stored in a 60-meter-high tower, a landmark in Leiden, opened in April 1998. Some parts of the collections are stored in a depot in the former museum building at the Raamsteeg in the city center of Leiden.

The Index Herbariorum code assigned to Naturalis is L and it is used when citing housed herbarium specimens.