Travelling to South America

[theBruiser500]

What is special about the Dominican Republic? I am leaning towards Lima now because there is something specific and cool to do there (Machu Pichu). A couple other specific things that people have told me about are, some volcano that is still active but don't know what country that's in. A week long tour through the amazon which sounded great, but not sure which place is best to go for that. Not Brazil becuase I want to do SPnaish.