The villages of Buna and Gona became Japanese bases during WWII and were the scene of some of the most desperate fighting of the war. At Giropa Plantation, on the Buna Rd, a Japanese plaque commemorates the country's dead.
Most of what remains of the bases is covered with overgrowth and a guide is necessary to work out what went on where. Basil Tindeba, from Buna, knows his way around the area pretty well; ask for him at the Oro Guesthouse and try to give a few days' notice. Another recommended guide is Maclaren Hiari MBE, who runs the Kokoda Buna Historical Foundation (tel: 329 7627). He lives two doors east of the Oro Guesthouse. These guys charge for their guiding and will generally arrange to take you by PMV and boat to both sites, which is important because without a boat you can't get from one to the other without returning to Popondetta. Another good option is Pol Toki at the Birdwing Butterfly Lodge, who supplies a truck and also takes in Seremi village, the scene of George Silk's famous photograph of Fuzzy Wuzzy Angel Raphael Oimbari leading blinded Australian soldier Dick Whittington.