フリースラント諸島
Mandø is geographically one of the northernmost islands among the North Frisian Islands off the southwestern Danish and northwestern German coast. The Frisian Islands are generally the line of demarcation separating the North Sea from the Wadden Sea, which is a shallow sea of approximately 5000 square kilometers in size, riddled with small islands and tidal flats. The entire Wadden Sea area was formed by intervening riverine depositional periods between Ice Age glacier movements.