But lying there, in Central Park, I wasn’t yet exhausted. I thought about how, when I first started sleeping out, I found it hard to unwind. The night was too quiet. I felt vulnerable without locked doors and electric lights. The absence of distraction–television, phone, refrigerator–was unnerving. The tent was claustrophobic. Even in the wilderness, the night itself seemed hemmed-in, forbidding. It was only gradually that I learned to relax and to appreciate the night. At this point, I think I have become one of those people who goes to the woods not to hike, but to stop hiking–to get to a clearing, pitch a tent, and be surrounded by night. I’m not a snob about the location. A hard-to-reach, private spot is nice, but car camping works fine for me, too. The long chill nights of late fall or early spring are ideal. My preference is to keep comforts to a minimum–no super-inflated mattresses, no pillow. I want to feel the ground. One night I slept at the base of Ausungate, a spectacular mountain in the Peruvian Andes that remains sacred to local indigenous people. I had hiked for two days in dreary, overcast weather and hadn’t caught even a hint of the peak said to be shrouded beneath the clouds. I was beginning to wonder whether the mountain existed at all. I went to sleep early and woke a few hours later with a start. I stepped out of the tent: The night sky had cleared. Ausungate, covered with glaciers, lit by stars, was glistening in front of me, as though it were being drowned in floodlights. It was a vision of the mountain, and more–a glimpse, it seemed, of the interior of night.