I recently finished The River of Doubt by Candice Millard. Join an amazing mapping expedition down an unexplored river in the Amazon jungle. It is 1914. Your guide is the Brazilian hero Candido Rondon, and your leader is Teddy Roosevelt with naturalist George Cherrie. With such leadership, what could go wrong? Well everything actually. Their challenges were epic as they overcame one obstacle after another just to survive let alone navigate this wild river. A bonus is the author's descriptions of the surprising synergies between plants and animals in this jungle.