Often referred to as a ‘medical city’, Rotterdam’s academic hospital Erasmus MC is indeed a dense urban complex designed in 1965 by Arie Hagoort (OD205) in collaboration with Jean Prouvé. What is today KAAN Architecten's Educational Centre used to be an open courtyard named Level 2, designed by Hagoort as a connecting promenade between different wings — however, as it was rarely used, the decision was made to turn it into the library and learning centre it is today. Creating a dramatic sense of height and openness, KAAN Architecten added a column-free roof with triangular openings that allow for natural light to seep into the building. The triangular motif and the linear patterns that it creates is repeated throughout the Educational Centre, echoing the former building’s diagonal lines and trajectories, leaving the concrete spiral staircases descending into the main library pit the only thing to remind us that this used to be once an exterior space.