One of the most dangerous and toxic today is the Citarum River in Indonesia. What made it this way? How do people live on the banks of this river? What efforts are being made to purify it? Citarum is ...

It is one of the world’s most significant waterways, stretching across Peru, Colombia and Brazil. It is home to the world’s largest species of river dolphin and some 60 species of piranha.

We've picked some of the world's greatest rivers to profile -- the longest, deepest, widest or simply the most beautiful. Whether you're after pristine isolation, lush wilderness, exotic animals ...