This is the "A View on the Tiber" by Jan Both. Painted in the early 1640s, it's one of a series of Italianate landscapes that he made after spending ten years in Italy. What makes this painting unusual for Both is its focus on an urban view - the old port of Rome's Ripa Grande - rather than a landscape.
The scene is partly imaginary, with some of the buildings and details added by the artist to enhance the sense of atmosphere and light. The tall central tower in the background is recognisable as Santa Maria della Torre, but the rest of the buildings are invented by Both.
In this painting, we see hardy peasants going about their daily lives, enjoying the evening sun. They're engaged in various activities - playing cards, smoking, or working on the roof. One figure, wearing a red hat and gazing intently at the view, is shown in more detail than the others, suggesting that he may be an alter ego of the artist himself.
The distant landscape is misty, with golden light casting shadows over the still water of the Tiber. It's as if the viewer is looking so intensely in order to remember what they see, much like Both must have done when creating this painting on his return to the Netherlands from Italy.
A View on the Tiber 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.