Cape MacDonald is a headland

Headland

A headland is a point of land, usually high and often with a sheer drop, that extends out into a body of water.Headland can also refer to:*Headlands and bays*headLand, an Australian television series...

 which rises to 435 m, forming the south side of the entrance to Odom Inlet

Odom Inlet

Odom Inlet is an ice-filled inlet 9 miles long, between Cape Howard and Cape MacDonald along the east coast of Palmer Land. It was discovered by members of the US Antarctic Service who explored this coast from East Base both by land and from the air in 1940, and named for Howard Odom, radio...

, on the east coast of Palmer Land

Palmer Land

Palmer Land is that portion of the Antarctic Peninsula which lies south of a line joining Cape Jeremy and Cape Agassiz. This application of Palmer Land is consistent with the 1964 agreement between US-ACAN and UK-APC, in which the name Antarctic Peninsula was approved for the major peninsula of...

. Discovered by members of the United States Antarctic Service (USAS) who explored this area by land and from the air in 1940, and named for J.E. MacDonald, field representative and secretary of the USAS.