This is "A Frozen River by a Town at Evening" painted in the style of Aert van der Neer around the Low Countries. You can see how the river has frozen hard, reflecting back a dramatic sky with dark clouds tinged with a warm russet glow from an unseen sunset.
Van der Neer was one of those artists who specialised in winter scenes during this period. His paintings often show a relatively light dusting or heavy frost, and not thick snowdrifts. This is not just about the beauty of winter landscapes; it's also about capturing the imagination of his clients and the changing times.
Notice how the figures are types, carefully positioned for effect rather than being part of a real moment in time. Here they seem lonely, scattered across the ice. You can see one man playing kolf, a game between golf and ice hockey, on his own while another plays nearby.
There's also a squatting figure behind the tree, though this has been overpainted at some point. This kind of earthy humour was common in Dutch painting back then but clearly not to everyone's taste.
The paintwork itself is oil on wood, characteristic of many paintings from around that time and region. The style suggests it might have been made towards the end of a particularly cold period, known as the Little Ice Age, which lasted for several decades.
A Frozen River by a Town at Evening 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.