Due to its geographical location in what used to be wet peatland, the founding of Amsterdam is of a younger age than the founding of other urban centers in the Low Countries. However, in and around the area of what later became Amsterdam, local farmers settled as early as three millennia ago. They lived along the prehistoric IJ river and upstream of its tributary Amstel. The prehistoric IJ was a shallow and quiet stream in peatland behind beach ridges. This secluded area could grow there into an important local settlement center, especially in the late Bronze Age, the Iron Age and the Roman Age. Neolithic and Roman artefacts have also been found downstream of this area, in the prehistoric Amstel bedding under Amsterdam's Damrak and Rokin, such as shards of Bell Beaker culture pottery (2200-2000 BC) and a granite grinding stone (2700-2750 BC). But the location of these artefacts around the river banks of the Amstel probably point to a presence of a modest semi-permanent or seasonal settlement of the previous mentioned local farmers. A permanent settlement would not have been possible, since the river mouth and the banks of the Amstel in this period in time were too wet for permanent habitation.