Telésforo de Aranzadi (1860-1945) was a great anthropologist from the first decade of the 20th century. He worked with José Miguel de Barandiaran (1889-1991) and Enrique Eguren (1888-1944), researching on the prehistory and origins of the Basque people. This room is dedicated to Aranzadi, and includes diplomas, pictures and other original documents of the Basque anthropologist.

In the central display stands we find a vast and interesting collection of fossilized dinosaur bones from the Laño site in the Basque Province of Araba. The site was excavated by professors Xabier Orue-Etxebarria, Humberto Astibia and Estíbaliz Apellaniz from the Faculty of Science and Technology of the University of the Basque Country. There is also a collection of minerals and a collection of medical botanical plants (which is not open to the public due to the lack of space).