After they passed by the eaves of Lórien, the waters of the Great River Anduin flowed into a wide, flat land, so that for many miles the river was shallow and filled with shoals and eyots. As part of its path through this region, the river's course swung out into two wide westward loops, the Undeeps. The southern loop, the South Undeep, was the lesser of the two, but still saw the river divert from its course by some thirty miles.