The seldom used track (except now for Australian tourists) is located in the Oro province of Papua New Guinea. It starts near Buna and Gona on the north coast of Papua led easily up slopes to Kokoda to the south. Kokoda stands on a small plateau some 400 metres above sea level and is surrounded by mountains rising above 2,000 metres. The Kokoda track was formed by gold miners during the 1890's moving from Port Moresby to the gold fields of Yodda and Kokoda. The Kokoda track is significant in Australian history because of the events surrounding the Battle of Isurava.
"Between Kokoda and Ilolo (a village a short distance to the south of kokoda), the track often climbed up gradients so steep that it was heartbreaking labor for burdened men (often carrying packs of 40kgs) to climb even a few hundred yards. Much of the track was through dense rain forest which enclosed the narrow passage between walls of thick bush. At higher levels the terrain became moss and stunted trees which were often covered in mist. From July to November 1942 this was the setting for a bitter campaign to prevent the fall of Port Moresby." http://www.pacificwrecks.com/provinces/png_kokoda.html
The Kokoda track is skinny and runs through dense rainforest with walls of thick bush making the track very narrow. At higher mist shrouds moss covered trees. The track is rainy, slippery, muddy and leech infested.
From Kokoda the track leads over very steep ridges and deep valleys, to the south, through Deniki, Isurava, Kagi, Ioribaiwa, Ilolo and at Owens' Corner linked with a road proper through the plantations above Port Moresby down to the town on the coast.
Note: preferably called 'Track' by Australian veterans instead of the officially recognised but Americanised 'Trail'.