The Japanese stronghold position was about long from north to south, and wide. The terrain within this area comprised a series of small jungle-covered ridges, and the position was bordered on the western and southern sides by swamps. The main terrain features within the Pocket were three areas of high ground named Lushington Ridge, Norman Ridge and Lyon Ridge by the Australians. There were only two feasible routes into the area. The first was a track which led south into the position along Lyon Ridge and Norman Ridge; this was passable by tanks but heavily mined. The other route was a track which ran into the eastern side of the Pocket from MacArthur Road along Lushington Ridge and joined the other track at Norman Ridge. It is likely that around 250 Japanese personnel were initially stationed within the Pocket.