Heart of Darkness vs. Apocalypse Now

For me the most striking, albeit most obvious, difference between Joseph Conrad's novel Heart of Darkness and the Francis Ford Coppola film Apocalypse Now was the change in setting.   Heart of Darkness is set in the Belgium Congo as Leopold II attempts to expand his colonial empire just before the turn of the century.  In Apocalypse Now the setting is moved to war torn Vietnam in the 1960s.  Despite the change in setting the underlying stories are the same.  This shows the common nature of conquest and that in any state of subjugation there will always be imperialists and authoritative, power hungry men like Kurtz.  The differing settings highlights the similarities between the two stories and shows the transcendence of Conrad's original novel.