Is a wonderful journalist for The New Yorker and both of his books are worth reading. One is a collection of essays for the magazine (maybe some others - I'm not positive)

The other is a full-length piece about explorers searching for a lost city in the Amazon.

If you get real into the Amazon after taking this suggestion (omg I just realized my links are to Amazon, I dunno, I'm slow today, but neat) try witnessing Teddy Roosevelt's post-presidential expedition there.