Słowiński's moving dunes bury a living pine forest, then hand it back decades later. Westerlies off the Baltic drive mountains of pale sand inland at three to ten metres a year — Łącka, the highest, rises about 42 metres — and the pines in their path go under crown-first. Long after the sand has passed, the wind strips it away again and uncovers what it killed: bare, bleached trunks standing in the open. The sand comes off the beach; currents deliver it along the shore, the wide strand dries it, and the wind carries it inland. The same drifting sand built the bar that sealed two Baltic bays from the open sea, stranding Łebsko — Poland's third-largest lake — and Gardno behind the dunes. UNESCO made the park a biosphere reserve in 1977 and its wetlands are Ramsar-listed. The name belongs to the Słowińcy, a Baltic people no longer here.
Cars stop at the Rąbka gate outside Łeba. From there it is about five kilometres of flat, shadeless walking — ninety minutes, or less by rented bike or electric cart — past the concrete pads of a wartime rocket range, until the pines simply stop. Climbing the dune means wading ankle-deep with no path underfoot; the wind wipes out your footprints within minutes and recombs the ripples overnight. From the crest the view splits: white sand, dark forest on one side, the grey Baltic on the other, dead trunks marking the sand's advance. In summer the surface gets hot enough to burn bare feet. The strongest winds blow in autumn and winter, when the dunes travel fastest, and most walkers come back along the empty beach below. Nothing here is settled — the dune is still moving east, and the forest in front of it is next.