In secondary science education, students often do not feel engaged with the scientific concepts that are taught, which hinders conceptual learning. This lack of engagement can be overcome by fictional placemaking. Therefore, the purpose of our design-based research is to explore how the creation and use of fictional places lead to meaningful contexts providing opportunities for the learning of biology. Four design principles were formulated from theories on: (1) pedagogy of place; (2) communities of practice; (3) imaginative teaching; and (4) story-based learning. Based on these principles a lesson series was designed in which students were challenged to create societies living in domes on Mars as a fictional place. This lesson series was conducted in a ninth-grade class (28 students) at pre-university level. It was evaluated on the contribution of the design principles to create a meaningful context for the learning of biology. This research focuses on causal reasoning, which is a key competency in biology. The analysis of artefacts of group work showed evidence that students expressed different types of causal reasoning. Reflection on each of the design principles made clear how fictional placemaking provides opportunities for the development of students' causal reasoning.