The aim of this research is to investigate the effect of enriched learning environments which have been developed in the framework of the "erosion and landslide" concepts on the conceptual understanding of students. A quasi-experimental method has been used in this research. The sample consists of 40 students. 5th grade students (aged 11-12) selected from a primary school in the province of Trabzon in Turkey. To collect data, the researchers used concept test, interview consisting of semi-structured questions and drawing test. When the post test results are examined, a significant difference is identified in favour of the experiment group (U=128,00, p<0.05). However, the fact that students were not able to reflect this result to their drawings is striking. In the post drawings made on the concepts of erosion and landslide, the number of students who did not make any drawings in the experiment and control groups is quite high. This result can be stem from student's operational periods. 5th graders are in the process of transition from the concrete operational period to the abstract operational period. They had problems to reflect their thinkings to drawings. Ready-made pictures were utilized in the poster assignment used in this research. A poster activity which includes the drawings of students can be carried out in a future research.