Line pathway with rocks painted with glow in the dark paint. During the day they “charge” - in the evening they reflect. Rust-Oleum Glow in the Dark Brush-on Paint. For a temporary method- 1/4" Moiuntain Dew in bottle, add tiny bit of baking soda and 3 capfuls of hydrogen peroxide. Shake and it glows. Pour on sidewalk to "paint".