The Overland Track is a six day walk of 65 kilometres through the heart of the Tasmanian Wilderness World Heritage Area.  It extends from Cradle Mountain in the north to  Lake St Clair in the south.  The Track is a true wilderness walk which travels through spectacular dolerite mountains, past beautiful waterfalls, close to Mount Ossa -Tasmania's highest mountain - and through a variety of fascinating alpine ecosystems. 

The stunning scenery and the physical challenges of this mountain walk have ensured that the Overland Track has built a national and international reputation as one of the great wilderness bushwalks.  Bookings are essential if you wish to do the walk.  Numbers of people on the track are limited each day.

You must read the National Park webpage here.

There are several companies which conduct fully escorted walks of the Track: 

There's some comparative information about these companies on the bottom of this National Parks page here.