In the Rio Abajo jungle of central Puerto Rico, the Rio Tanama flows down waterfalls and through abandoned hydroelectric plants--now ghostly and vacant--on it's path through Charco Hondo, a region south of Arecibo. As one travels upriver, jumping rusty fences and tiptoeing the meandering path, the foliage presses in until, finally, an opening appears as a perfect pool of green--the quintessential swimming hole complete with tattered rope swing slung upon a yonder vine.