The phrase "treacherous lands" refers to places or areas that are dangerous, difficult to navigate, or likely to cause harm or accidents. Full definition
The journey takes Bilbo on a path through treacherous lands swarming with orcs, goblins and other dangers, not the least of which is an encounter with Gollum (Andy Serkis) and a simple gold ring that is tied to the fate of Middle Earth in ways Bilbo can not even fathom. (mrqe.com)
Their journey will take them into the Wild; through treacherous lands swarming with Goblins and Orcs, deadly Wargs and Sorcerers. (dvdmg.com)
Cattle Dogs pull ahead as the winner for hotter climes due to their medium length coats which allow them to not only survive but thrive in treacherous lands such as the Australian Outback where they were originally bred to drive cattle. (animalso.com)