Whereas the literature is clear on the benefits of large displays and visualizations, little is known about their combination, that is, how display size affect the usability of visualizations. We describe a controlled experiment where 19 participants used focus+context, overview+detail, and zooming techniques with varying display sizes (13.8, 1.5, and 0.17 megapixels). Participants navigated geographical maps to find specific locations, compare items, and follow routes. Results show that for multi-scale navigation, classic interactive visualization techniques did not benefit from being scaled to a large display: In contrast to the literature we find similar performance on medium and large displays. Across display sizes, overview+detail works the best, in particular for comparing items. Focus+context is relatively more difficult to use at a small display size. We explain these findings and discuss the design of interactive visualization techniques for large displays.