Yedigöller is a chain of seven lakes strung down one valley of beech forest in Bolu province, in northwestern Türkiye, no two the same colour, formed by landslides that dammed the stream, and it is the forest that the country drives north to watch turn each autumn, walked on a path that links all seven lakes and stayed in overnight for the two hours of quiet that matter. The lakes sit in two groups, Büyükgöl, Deringöl and Seringöl below and Nazlıgöl, Kurugöl, İncegöl and Sazlıgöl on the shelf above, linked by a path of a few kilometres through beech, oak, hornbeam and fir, with a waterfall where the outflow of Nazlıgöl drops away through the trees, and Kurugöl, the dry lake, cannot fill itself and holds water only for a few weeks of the spring melt before it is grass again; the colour comes from mid-October into the first half of November, peaking in early November, when the oriental beech turns gold and copper and the oak and hornbeam go rust, with the firs staying green among them so the slope reads as a mosaic rather than a wall of red, and the fallen leaves lie ankle-deep on the lower lakes with the canopy the same copper as the leaves on the water. Cold autumn nights over water still warmer than the air leave mist lying on the lakes at first light for about an hour.
The park fills on the autumn weekends with cars from Istanbul and Ankara, three hours away, so the campsite inside it is the way to have the place, since staying means being there for the evening when the last cars pull out and the dawn before the first arrive. In January 2026 a camera trap at Deringöl filmed a Eurasian otter, an animal that settles only where the water runs clean and the fish are healthy, and the forest holds deer, bears and wild boar. Yedigöller is seven lakes in one beech valley, and the country comes for the two weeks the leaves turn.