Underfoot: where the surface changes
The closest layer is the one people actually need. Treads, landings, the lip where a patio meets a lawn, the point where a walk narrows or turns. Light here is low, frequent, and quiet, and the aim is to reveal an edge rather than to make a feature of the fixture. Over-lighting this layer is the single most common mistake, because bright points at ankle height sit right in your line of sight.