For centuries, visual depictions of data and of the world have been used to understand and communicate information in novel ways. A prime example is cartographic maps of earth and water that have guided human exploration. They have marked the border between the known and the unknown, firing the imagination and fueling the desire for new knowledge and new explorations. Over time, geographic maps have become more detailed, more accurate and more sophisticated. Despite these advances, the thirst for exploration and discovery, along with the need for maps to guide our travels, remains undiminished.