Located in a building that was originally a 13th-century Dominican convent, the Musée Unterlinden is one of the most-visited museums in France, and has a collection of religious art that outnumbers that of the Louvre. Established in 1853 in Colmar, France—the town’s charming homes were the inspiration for the animated Disney version of Beauty and the Beast—the Musée Unterlinden recently underwent an expansion by Herzog & de Meuron, who was awarded the job in 2009, that connected the institution to an early 20th-century public bath building.

The museum’s crown jewel, no doubt, remains the Isenheim Altarpiece, which was sculpted and painted by Niclaus of Haguenau and Matthias Grünewald between 1512 and 1516, and it has been restored its original glory. The museum also has a number of paintings and sculptures by Pablo Picasso, Fernand Léger, and Jean Dubuffet.

“The Unterlinden Museum is a truly international institution,” said Pierre de Meuron, senior partner at Herzog & de Meuron. “On the one hand, its collection—together with, in particular, the Isenheim Altar—is an integral and central part of the cultural heritage of France on the periphery of which the museum is situated. On the other hand, the collection represents a core part of Europe’s cultural heritage as a whole, while also serving as an invaluable manifesto thereof. It is our hope that the Unterlinden Museum will come to be seen as an institution standing for the history of Europe, and this above and beyond any national boundaries.”

Herzog & de Meuron sought to keep the historical integrity of both of the buildings in place while adding contemporary touches. The firm designed a passageway-cum-gallery space that begins with a spiral staircase and fuses together the former convent and the bathhouse. The design pays tribute to the location of the structures, keeping in tact the canal that ran through the area, and by recreating a structure that resembles the farm buildings that were located throughout. The space that once belonged to the municipal pool has been turned into an events area that will hold both parties and talks.

“The interplay between city planning, architecture and museography renders the Unterlinden project most exceptional: one leads to the other,” said Jacques Herzog, senior partner at Herzog & de Meuron. “From the angle of urban development, the most decisive contribution is the enhancement of the formerly desolate zone between the cloister and the former public Baths. Then, the opening of the formerly covered canal provides an attractive site for Colmar: it is here that the entrance to the new museum complex has been transferred. And still another exceptional aspect: only close scrutiny distinguishes the old from the new architecture of the complex’s various parts.”

Visitors no doubt will be impressed not just by the collection of the Musée Unterlinden, but also by its new expansion. “Visitors will experience the expanded Unterlinden Museum as an organic, complex sequence of inside and outside spaces,” said Christine Binswanger, senior partner of Herzog & de Meuron. “In our profession, only rarely do we have the occasion to custom tailor architecture to such a degree, to a content that spans several centuries. We had a chance to simultaneously, and equally intensively, address changes to the urban fabric as well as the presentation of a single work of art.”