Söderbybyn is a village in Östhammar Municipality, in Uppsala County, Sweden. Söderbybyn lies at 12 m above sea level. The nearest city is Upplandstuna, 34 km to the southwest. Beaches nearby: Krutudden (4.4 km), Tallparksbadet (5.2 km). Among the landmarks around are Valö Church (13.7 km), Harg Church (12.6 km) and Hökhuvuds kyrka (12.8 km).
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