The Museum of Natural Science at Ciutadella Park is a public institution of science serving the community. In the year 2000, the Geology Museum and the Zoology Museum merged, forming the current Museum of Natural Science.

The origin of these two museums goes back to the Martorell Museum, which was founded in 1878 from the bequest left by Francesc Martorell Peña. This was the first public museum in Barcelona. The Museum's entire holdings were originally housed at the Martorell building, but in 1924 part of the collections was transferred to the building known as Castell dels Tres Dragons ('Three Dragons Castle'), where the city's Zoology Museum was located until 2000.

The Museum is dedicated to preserving our natural heritage and promoting the zoological and geological holdings of the Museum, whose importance to the scientific, economic, and cultural development of society is evident. The Museum preserves, documents, and expands the collections in order to disseminate knowledge of our country's natural heritage and, in addition, to develop citizen awareness about the need to protect the natural environment.

As a cultural instrument, the Museum promotes the teaching and dissemination of the natural sciences through a variety of activities adapted to the needs and desires of society in general, and the schools in particular.