This map by the European Commission's Joint Research Centre in Ispra, Italy is an attempt to demonstrate what areas of the world are comparatively accessible by land and water travel. The cartographers concluded that much of the world commonly thought of as inaccessible is not:
The maps are based on a model which calculated how long it would take to travel to the nearest city of 50,000 or more people by land or water. The model combines information on terrain and access to road, rail and river networks (see the maps). It also considers how factors such as altitude, steepness of terrain and hold-ups like border crossings slow travel.
Plotted onto a map, the results throw up surprises. First, less than 10 per cent of the world's land is more than 48 hours of ground-based travel from the nearest city. What's more, many areas considered remote and inaccessible are not as far from civilisation as you might think. In the Amazon, for example, extensive river networks and an increasing number of roads mean that only 20 per cent of the land is more than two days from a city - around the same proportion as Canada's Quebec province.
Map Link and Article Link via Volokh Conspiracy
http://timetoeatthedogs.com/2009/10/28/the-remotest-place-on-earth/
It is worth a quick read if you are interested.