The path from Banos to Puyo runs along the north side of the Pastaza River and is known today as the Route of Seven Cascades. The name reflects the fact that numerous rivers from the north empty into the Pastaza and form waterfalls as they leap from the canyon walls cut by the Pastaza.  This is one of the smaller rivers from the north (draining an inaccessible region known as the Llanganates), but even a stream  of this size can turn into a fierce torrent during times of heavy rains.. In the 19th century,  the English naturalist Richard Spruce took 17 days to travel from Canelos to Banos, a 65-mile trek that he called "heart sickening" and so filled with suffering that he could "hardly bear to think of it."