One of the aims of the Independent Expert Commission (IEC) is to produce quantitative studies of the institutional landscape that will provide a more precise picture of the facilities that were used and the authorities that issued administrative detention orders. The charting of this institutional topography was facilitated by the surviving directories from the year 1933, from the 1940s, and from the years 1954, 1965 and 1980. The information they contain includes the names and locations of all the relevant institutions, together with key data concerning their purpose, maximum capacity, and the responsible authorities.With the help of DensityDesign Research Lab, the data collected was converted into interactive maps and visualisations that allow for a more detailed understanding of the temporal and spatial dimensions of administrative detention.