What is Princess bride fire swamp?

In the fictional world of the movie and the novel on which it is based, "The Princess Bride", the Fire Swamp is a treacherous and deadly swamp that must be crossed by the main characters, Westley and Buttercup, on their journey to reunite. It is described as a vast and sprawling mire filled with dangerous and hostile creatures, including giant rats, fire-breathing eels, and the dreaded ROUSs (Rodents of Unusual Size). The Fire Swamp is said to be so treacherous that even the most skilled swordsman would not dare to venture into it alone. Due to its dangerous nature, it acts as a significant obstacle and a trial that the characters must overcome in their pursuit of love and adventure.