This is the "A River Scene with Distant Windmills" painted in the Dutch north by Aelbert Cuyp. Made around 1641, when he was about 20 or 21 years old, it shows his early grasp of creating a sense of distance and capturing the mood of a cloudy day.
Look at how Cuyp used a very restricted colour scheme of greys, browns, and greens to evoke the atmosphere of the weather. He avoided too much gloominess by setting the horizon low on the canvas so that the sky dominates. You can see this in the way the sky fills the composition with airiness.
Cuyp also showed his talent for other subtle light effects here. The strongest shades are in the foreground, where the water almost turns black. But at the same time, the brightness in the middle of the painting lifts the atmosphere. And notice how the thin strip of land beyond seems to shimmer between water and sky.
The artist's influence can be seen in the way he used techniques from Jan van Goyen, a landscape painter who worked nearby. Both artists followed similar approaches in their work.
A River Scene with Distant Windmills hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.