The Sackwald is part of the geological structure of the Sack Basin or Sackmulde along with the Sieben Berge and the Vorberge.

The Sackwald lies on the eastern edge of the Leine Uplands in the Lower Saxon Hills.

The Sackwald is surrounded by the ridges of the Vorberge to the north, the southeastern foothills of the Hildesheim Forest to the north-northeast, the Sauberge to the northeast, the Harplage to the east-northeast, the Heber to the east, the Helleberg to the south and southwest, the Selter (on the other side of the Leine valley) to the southwest and the Sieben Berge to the northwest.

Several streams rise within or on the edge of the Sackwald, whose waters eventually empty into the westward-running Leine or the northeast flowing Innerste; the ridge thus lies on the watershed between the two rivers.

Also worth seeing are the ruins of the Schulenburg Chapel, which stand northeast of Langenholzen and north of Sack (both in the borough of Alfeld) at about 185 metres above sea level on the southwestern edge of the neighbouring Vorberge.