In the coming 20 years, the city centre of Rotterdam will face a new wave of constructions, with the goal of densify the area with new 50.000 dwellings before the 2040, converting the city centre towards a more residential and international character. This up-coming densification of Rotterdam, led by the high-rise strategy developed by the Municipality, it is going define a border condition between the new high-rise developments and the historical neighbourhoods, such as the case of Cool Zuid and Baankwartier, causing a disrupted relationship between the built environment, the public space, and the human scale, creating tension and dichotomy. Within this scenario, what could it be a different catalyst event, different from the high-rise strategy, that will lead the future of this neighbourhood, preserving its human scale while accommodating the future of the city? And so, “How is public space going to be reconsidered within the international character and the high-rise strategy of Rotterdam?”. Therefore, if the Municipality of Rotterdam will be more focused on the skyline of the city, the goal of the Open & Closed is to explore the so-called “groundline” of Rotterdam.Thus, the Open public space that today is only perceived as playground, a fixed mono-functional use, in the coming years it will be re-thought and designed as a more informal public space, where different users will start to interact and co-exist. Meanwhile, the Closed public space will be a new Performing arts centre, where the already present activities such as dance, music and theatre studios in the area will be reallocated in one public building. However, it will be important to make a strong synergy between the Open & Closed public space, made of visual and physical relationships that architecture can create, together with a public program to engage a broader audience, in response to the future growth and needs of Rotterdam.