Behind the beach at Provincetown and Truro are eight square miles of dunes, making a great series of dips and pockets, innumerable smooth scourings, hollows within wide hollows. Standing below their rims are hills, mounds, and cones, chiseled by the wind, sometimes flattened on the top like mesas. These dunes give an effect of motion, rolling, dipping, roving, dropping down and curving up like sea surfaces offshore. When I climbed the bank to see them I heard the clear, accomplished notes of a song sparrow. There were banks of rugosa roses in bloom, with white or pink flowers sending off a lovely scent, and the dunes were patched with the new green of beach grass, bayberry, and beach plum, many of the shrubs looking clipped and rounded, held down by wind and salt spray. The purple and pink flowers of the beach pea, with purselike petals, were in bloom too, contrasting with dusty miller with leaf surfaces like felt, a soft, clear grayish-green. Down at the bottom of the hollows the light and wind catching heads of bunch grass, pinkish and brown, waved continually; and the open sandy slopes were swept as by a free hand with curving lines and striations. A mile or so at sea, over the serene flatness of the waters, a fishing boat moved very slowly by. I started down the beach again, following another swallow that was twisting and dipping in leafy flight along the upper edge of the beach. On the tide line slippery green sea lettuce began to glimmer as if it had an inner fire, reflecting the evening sun. I stopped somewhere a mile or two north of Highland Light in Truro, built a small fire of driftwood to heat up a can of food, and watched a bar appearing above the water as the tide ebbed. Low white waves conflicted and ran across a dome of sand, occasionally bursting up like hidden geysers. The terns were still crying and diving as the sun’s metal light, slanting along the shore, began to turn a soft yellow, to spread and bloom. They hurried back and forth, as if to make use of the time left them, and fell sharply like stones into the shimmering road of light that led across the water.