This article uses viewshed analysis to study the relationships between different islands in the Archipelago of the Azores, in the context of a geographical analysis of the distribution of populations. The issue is whether "to see" or "to be seen" is a relevant factor influencing the choice of zones of habitation in the specific setting of the Archipelago of the Azores. The literature often focuses on the relationships of covisibility maintained between the different islands. Using an analytical method based on an algorithm of covisibility, we propose a quantification of these connections using a method based on a viewshed algorithm. The computing of viewshed algorithms is time-consuming. To overcome this problem, we propose in the first section a method of computing time based on the reduction of the number and the optimization of the placement of the viewpoints used for the calculation. The results show a significant drop in computing time. A second section of the paper presents a method of spatial analysis that makes it possible to determine and to quantify the grouping of inhabitants that can be seen from one island to another. The results are then analysed, and a chart is drawn up, and the chart is then discussed in a final section. Contributions to the study are on two levels. The first is related to the methodology, and is described before the second one. The second one, more geographical, points to the viewshed factor: of course the viewshed factor on its own does not explain the distribution of populations, but it sheds new light on the question. It also facilitates an understanding of the complex relationships that motivate these islands, in the very contemporary perspective of a reflection on new planning issues in the Azores Archipelago.