The Vivero Letter (1998) is an adventure movie starring Robert Patrick, Fred Ward and Tom Poster.
This movie is based on the 1968 novel The Vivero Letter by Desmond Bagley.
A man in Central America finds his brother's murdered body.
It turns out that his brother has been murdered because he knows the whereabouts of a lost city in the jungle.
The man teams up with a search expedition and goes off to hunt for these ancient ruins.