The thesis projects seeks to renew the relationship between the Royal Dutch Marine Camp and the city of Amsterdam. With the Royal Dutch Marines breaking an administrative agreement in July 2018 and deciding to continue occupy about 50% of the area on Marineterrein, the visions and ambitions for the development of a future-proof district had been compromised. The presence of the Navy Base in the city centre and the border that currently separates civilians from marines contradicts the character of the new development and is an anachronism that needs drastic changes. At the same time, mass-tourism and the expansion of NEMO museum onto Marineterrein poses a threat for the distraction of the tranquil character of Marineterrein with possible new touristic related attractions replacing local amenities as precedented already all around Amsterdam. The thesis project focuses on all these issues and tries to create an in-between space, offering facilities for both the civilians and the marines while retaining a peaceful character by redirecting the touristic crowds. The projects tries to diminish the use of high walls and fences and decrease the need for intensifying security, intelligent surveillance systems and defensive mechanisms by putting in place crime prevention strategies through environmental design. The border on Marineterrein is now transformed into a buffer zone, a safe and inclusive district for civilians and marines that offers opportunities for interaction, while renewing the relationship and integration of such institution onto the urban fabric.