Wall displays support people in interacting with large information spaces in two ways: On the one hand, the physical space in front of such displays enables them to navigate information spaces physically. On the other hand, the visual overview of the information space on the display may promote the formation of spatial memory; from studies of desktop computers we know this can boost performance. However, it remains unclear how the benefits of locomotion and overviews relate and whether one is more important than the other. We study this question through a wall display adaptation of the classic Data Mountain system to separate the effects of locomotion and visual overview. Our findings suggest that overview improves recall and that the combination of overview and locomotion outperforms all other combinations of factors.