It is named after the Dano-Norwegian navigator and explorer Jens Munk.

The island is located on the southern side of Pikiulleq Bay and north of the Fridtjof Nansen Peninsula, separated from the mainland by a 45 km long sound named Kagssortoq (Kattertooq), which has a width ranging between 0.7 and 6.5 km.

The southern part of the island is covered by an ice cap.

The island has an area of 470.7 km ² and a shoreline of 185.9 kilometres.

[1] Its southernmost point is Cape Lovelorn, projecting from a steep 280 m high headland at the northern limit of Umivik Bay.