Over the years the gravel has broken down a bit and is now mingled with sand, and this time of year it has many tiny blades of grassy weeds growing through it, so it makes a soft crunch underfoot. It always seems to me that as the light fades the crunching grows louder. The sound it makes changes from spot to spot, depending on a variety of factors I suppose, but I've grown so accustomed to the varied distinctive sounds that I think I could probably make the circuit of that part of the yard in total darkness, the gravel telling me where to turn.
I don't continue into full night, though, but always end the walk about the time the trunks of the pines to the south have become black striations supporting a mottled cloud of barely discernible needles silhouetted against the last glow of evening sky. Then I sit on the porch for a few minutes, until trees and sky have almost blended. I expect to hear the first crickets chirp any evening now. So far, it's still only the frogs. I'll probably only be able to spend the evenings outside for a little bit longer before the mosquitoes begin showing up. Ah, well. The best moments never last long.