During search, individuals direct attention to potential targets and remember locations visited. Previously this has been examined in visual search paradigms, but this thesis investigates these mechanisms of attention and memory in large scale search. Participants searched a room containing an array of illuminated locations embedded in the floor. The participants' task was to press the switches at the illuminated locations on the floor to locate a target that changed colour when pressed. Across all experiments, the perceptual salience of search locations was manipulated by having some locations flashing and some static. Adults and children (Age 6-12) are more likely to search at flashing locations - their attention is captured by the salience of the flashing lights, leading to a bias to explore these targets (Chapter 2 Experiments 1-4). This effect is robust and does not show developmental progression from 6years of age through adulthood (Chapter 3 Experiment 1). Both adults and children are more able to equally explore flashing and static exploration to flashing locations when not required to remember which locations had been previously visited, indicating an interaction between memory and attention mechanisms during search. This finding builds upon established work of load theory of attention during visual search. Further evidence for this memory attention interaction comes from search tasks with concurrent digit span or auditory tasks (Chapter 2 Experiments 3& 4, Chapter 3 Experiment 2). Finally I examine ability to learn likely target locations (Chapter 4) and find that adults are more able and faster, to learn likely target locations among salient targets. Overall, this thesis provides an account of the strong interactions between attention and memory during large scale search, and how these processes develop. It builds upon a framework from visual search literature to understand how these processes function and develop in a larger search environment