Fordon Valley (physical-geographical unit no. 314.83) is a mesoregion in northern Poland, forming the southern part of the Lower Vistula Valley.
According to the National Atlas of Poland (1978), the Fordon Valley borders:
The mesoregion lies entirely within the Kuyavian-Pomeranian Voivodeship and is named after Fordon, a former town now a district of Bydgoszcz.
The Fordon Valley was formed about 12,000 years ago when the flow direction of the Proto-Vistula changed from westward in the Toruà Â-Eberswalde Urstromtal to northeastward. The initial form of the valley and the Fordon Vistula Gorge was a sandur valley of the rivers Wda and Màtawa, later transformed into a proglacial valley and finally used as an outflow path for urstromtal waters toward the Baltic Sea.
The Fordon Valley stretches approximately 40 km from the Toruà  Basin to the Grudziàdz Basin, covering about 260 km<sup>2</sup>.
It begins where the river leaves the Toruà Â-Eberswalde Urstromtal (Notec-Warta basin) into its lower course along the boundary line considered as FordonâÂÂOstromecko, and ends below Cheà Âmno and à Âwiecie near the line SartowiceâÂÂPodwiesk. This segment shows contrasting changes in width. After the Fordon narrowing, about 3 km wide, the valley widens distinctly into a meander basin called the Unisà Âaw Basin, reaching widths up to 9 km. Then it narrows near Starogród, Kuyavian-Pomeranian Voivodeship to 5âÂÂ6 km, before widening again (about 7 km) near the mouths of the side tributaries of the Vistula: Fryba near Cheà Âmno on the right bank and Wda (Black Water) near à Âwiecie on the left bank. These are called the Cheà Âmno and à Âwiecie Basins.
The Cheà Âmno-à Âwiecie widening is genetically different from the Unisà Âaw Basin, reflected in their differing overall appearances and relief structures. The Unisà Âaw Basin formed due to lateral erosion of a Vistula meander, whereas the à Âwiecie and Cheà Âmno Basins formed through the widening of the main valley by side valleys.
Clear terrace system fragments remain in the Fordon Valley floor, allowing connection with terraces in the Toruà  Basin.
The mesoregion's boundaries are morphological. Because the Fordon Escarpment belongs to the à Âwiecie Plateau, the Fordon Valley includes the Vistula valley floor along with preserved terrace fragments. The current valley floor formed during the Late Glacial and Holocene erosion-accumulation processes, meaning it developed in several stages. In recent millennia, accumulation processes predominate, raising the floodplain level by about 4âÂÂ5 meters.
The valley floor consists of river alluvium with nine terrace levels; dunes and oxbow lakes (water-filled or peat-filled) are also present. The valley is protected from frequent Vistula floods by flood embankments.
The right bank near Cheà Âmno is deeply incised by ravines; exposures on steep slopes allow reconstruction of the Lower Vistula region's history during the last glaciation. Particularly picturesque hills above the river course can be found near Kozielec and à Âwiecie (Devil's Mountains, Wiàskie Mountains, Devil Mountains).
The valley floor is used for arable land and meadows and has scattered settlements. Fertile river alluvium averaging 2âÂÂ3 meters thick covers Holocene river deposits on sandy sediments from the Eemian interglacial or directly on Tertiary formations (sands, silts, clays).
Near Ostromecko, Rafa, and Cheà Âmno fragments of riparian forests with poplar, oak, elm, ash, and alder remain, partially protected in nature reserves.
The Fordon Valley covers parts of the municipalities of Bydgoszcz, Dàbrowa Cheà Âmià Âska, Dobrcz, Unisà Âaw, Pruszcz, Kijewo Królewskie, à Âwiecie, and Cheà Âmno. The main urban center is Bydgoszcz (Fordon district). The town of à Âwiecie is located on a terrace near the mouth of the Wda, one of the older Pomeranian towns, captured in 1309 by the Teutonic Knights who built a castle there. Fordon, incorporated into Bydgoszcz in 1973, was a castellany stronghold in the 12th century. It is connected by the road-rail bridge with the village of Ostromecko on the right bank of the Vistula, where there is an exploited source of alkaline water and the historic Ostromecko Palace and Park Complex of the Mostowski and Alvensleben families.
Valley of Death () in Fordon, Bydgoszcz, northern Poland, is a site of Nazi German mass murder committed at the beginning of World War II and a mass grave of 1,200âÂÂ1,400 Poles and Jews murdered in October and November 1939 by the local German Selbstschutz and the Gestapo.
T. Gacki and J. Szukalski in the work "Lower Vistula Valley" distinguished six microregions within the valley floor:
In the work "Natural Environment of Bydgoszcz", two microregions were distinguished in the southern part of the mesoregion (Bydgoszcz area):
The Fordon Valley is part of the Cheà Âmno and Nadwià Âlaà Âski Landscape Parks complex and two Natura 2000 sites:
Among the nature reserves in the mesoregion are:
More reserves occur on the valley slopes, which belong to neighboring regions: the à Âwiecie Plateau and Cheà Âmno Lakeland.
Noteworthy are the reserves protecting steppe vegetation on valley slopes: Pà Âutowo Nature Reserve, Zbocza Pà Âutowskie Nature Reserve, Mount St. Lawrence Nature Reserve and the forest Las Mariaà Âski Nature Reserve.