 The Japanese stronghold position was about 1 @,@ 200 yards ( 1 @,@ 100 m ) long from north to south , and 600 yards ( 550 m ) 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 . 
