Uppsalaåsen is an esker ridge that winds its way across Uppland in Sweden. The ridge disappears and reappears, typically locally named. In the south it begins on southernmost Södertörn and runs north-east, crossing Mälaren via Ekerö and Munsö and reaches the mainland at Bålsta. It then continues across the Uppland landscape and past Uppsala, eventually in the form of Billudden disappearing into the Gävle Bay. The ridge continues on the seafloor and curves northwest, appearing at Sandarna on the Hälsinge coast. The ridge is estimated to be 250 kilometers long, with maximum width about 1 km, and height about 75 m.