The Belo Monte Dam is currently under construction on the Xingu River in northern Brazil. Once completed, the $18 billion project is expected to have the capacity to produce 11,233 megawatts of energy, putting it third in generating capacity behind The Three Gorges Dam and the Itaipu Dam.
Opponents claim the dam could displace up to 40,000 people and impact roughly 1,500 square kilometers of the Amazon River basin. And, according to one estimate, it will take 41 years for the dam to have a positive impact on greenhouse gas emissions.
Click through the gallery for a behind-the scenes-peek at one of the most controversial dams ever proposed.