There are over 100km of marked walking trails in Nitmiluk National Park, from numerous 1-5 kilometre half day walks to a 66 km five-day trek!
The walks lead to waterfalls and lookouts over the gorge and Park. For the 66 km adventure, you can walk from Nitmiluk Gorge to Leilyn (Edith) Falls spanning 5 days; see here for a local's account of the walk about where you will sleep under the stars near amazing waterfalls each night: http://www.ourterritory.com/katherine_region/jatbula_edith_nitmiluk.htm
There is also an overnight 40 km return walk to the Eighth Gorge to view the Jawoyn Valley ancient Aboriginal art sites or why not try a 23 km return walk to Biddlecombe cascades?
For more information on these and other great walking tracks talk to staff at the Nitmiluk Visitor Centre. Please note, all walkers must register there before attempting any of the walks.
See here for road condition information: