This painting is by the English painter Joseph Gandy (1771–1843), and is called Jupiter Pluvius, and is dated 1819. We saw it at the Tate Britain last spring, on loan from Ray Harryhausen (1920–2013), a legendary stop-motion animator. Harryhausen took “a huge inspiration” from this painting.
You can tell by the image that Gandy and his brothers were architects, no? The setting is an ancient Greek town named Lebadeia, and now called Livadeia. I can’t tell why this place appealed to Gandy as a setting for this imaginary architectural complex, as there are no heights next to the real river. Maybe the name was what appealed to him? Given how many figures are on the bridge, it’s interesting how many areas there are basically empty of humans.
This is an appeal to the imagination and being calm, as we hear about real-world destruction by earthquake and hurricanes, as Jupiter Pluvius is the rain-giver version/aspect/epithet of this god of sky-weather-thunder.