The city hall of Leiden, designed by C.J. Blaauw and built in 1934, an exceptional building characteristic for the city of Leiden, is now facing an important challenge. The existing monument will one hand be preserved and adapted to the new needs of the municipality. Moreover, the challenge that the city hall faces is in relation to the city itself: to become a place where citizens and visitors enjoy coming; and in which they receive a warm welcome from the municipality and its board of directors. The square in front of the city hall will become a point of connection between the building itself and the historic city center and its cultural and historic institutions. The courtyard of the city hall will become an Hortus Conclusus with a spectacular tulip tree at its centre: the tree that Boerhaave planted in the Hortus Botanicus and on the Oud Poelgeest estate. With targeted, respectful interventions, the city hall will again become fit for purpose.