The area around Port Marly on the river Seine just to the west of Paris has been described as the cradle of Impressionism. The principal landscape painters in the movement all painted extensively there in the late 1860s and early 1870s. Pissarro, like his Impressionist colleagues, was fascinated by the play of light across water. In this work, he uses lively white impasto touches to suggest shimmering reflections. Pissarro carefully represents the wooden posts of a weir (a small dam) that diverted the flow of the river Seine. In the middle ground, he animates his composition with red roofs that offset the surrounding greens.