The island was named by officer of the Danish Navy Wilhelm August Graah and it was the northernmost point he reached during his 1828-1830 expedition along the southeast coast of Greenland.

Its highest point is a 430 metres (1,411 feet) high summit topped by an ice cap.

[2] The tiny sound of Timmiarmiit Tunorqtariât divides it from the mainland in the north.

[2] The island's coastline is irregular with bays in the north and the west, as well as an inlet on its eastern side between two peninsulas.

There is a cairn standing at a height of 217 m on the northern peninsula of the eastern side of Dannebrog Island.