River of Death (1989)

"The last chance to stop the rebirth of the Master Race."

An adventurer (Hamilton) decides to go in search of the Lost City in the Amazon jungle. A motley crew of other people decide to join him for the wealth of the city, for reasons of their own. But to their horror they find out that they have bitten off more than they can chew, what with a Nazi doctor still using the place for his human experiments.