The first library of the university of Basel was inaugurated in 1559 in the Brabeuterium, a chapel-like building precariously overhanging the Rhine river. Its starting collection of 240 volumes grew steadily with the absorption of other faculty libraries, belying the idea that library mergers are a distinctly modern occurrence. In 1671, the library moved to the Haus zur Mücke, where it stayed for nearly two centuries before moving in with the city museums in 1849 in a building that is now the Natural History Museum. By then, the library collection had grown to over 200,000 books and the new digs were hardly adequate. In 1890, the city council voted for the construction of a dedicated library building. Basel architect Rudolf Emanuel La Roche designed the new library in neo-Baroque style, with two symmetrical wings meeting in a cupola-covered entrance atrium. The wings were built using the then en-vogue load-bearing iron stack model.
New plans to expand the library were first drawn in the 1930s, but were put on hold during the Second World War. Finally, in 1959, the credit for the expansion was voted, and the project awarded to another Basel architect, Otto Heinrich Senn. His plans called for the near totaling of La Roche’s barely 70 year old building. Even though it was partly justified by the inherent lack of flexibility of the iron stack model used in the previous building, critics bemoaned this radical plan, in particular the replacement of the once distinctive cupola building by an austere functionalist facade and the loss of the baroque reading rooms. One of the original book stack wings was however spared, and still serves to this day. The intimate newspaper reading room in the old wing also preserves some of the atmosphere of the 19th century library. Construction of the new library was done in three stages between 1959 and 1968.
If Senn removed an visually distinctive feature by tearing down La Roche’s cupola, he more than adequately made up for it through another striking architectural feat. The sculptural concrete ceiling of the hexagonal main reading room leaves no visitor indifferent, and is still cited today as one of the best examples of functionalism in Switzerland. The room has been carefully renovated in 1998-2004 by Mathis Müller, with a particular attention to the original wood, glass, aluminium and concrete materials.

These twisted concrete pillars are testament to the engineering prowess of crowning an hexagonal room with a pentagon lantern. Also, a trip hasard.
References
- Historisches Seminar der Universität Basel/unigeschichte (2010). Erweiterungsbau und Erneuerung der Universitätsbibliothek in den 1960er Jahren. Unigeschichte.unibas.ch.
- Heusler, Andreas (1896). Geschichte der Öffentlichen Bibliothek der Universität Basel. Festschrift zur Einweihung der Bibliothek in Basel am 6. November 1896.