This is "A View near Venice (?)" by Francesco Guardi. Painted in the late 18th century, it captures a moment in time that's both casual and structured at the same time. You've got men chatting, women doing laundry, and a lively boy with his dog in the foreground, but they're all set within a very precise composition. Notice how the rooftops recede into the distance, drawing your eye towards the waterfront. The deep shadows across the ground create a sense of depth too. Guardi's use of thin paint gives the impression that the foreground buildings are almost sketchy, with hastily dashed-off lines suggesting windows and stonework.
A View near Venice (?) 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.