Kurefjorden is a 6 km sidearm of the Oslo fjord and is perhaps the best all-round site in Østfold. The inlet is rather shallow and thereby attractive to a substantial number of ducks, divers, Great Crested Grebe, Slavonian Grebe (autumn and winter), gulls and terns. The two bays Rosnesbukta at the head of the fjord and Ovenbukta a bit further out have both extensive mud flats exposed at low tide, providing excellent shorebird habitat. Most regular migrant species can be found resting here in season. It is perhaps the most regular site for resting Broad-billed Sandpiper (May/June and August).