An Arab Caravan outside a Fortified Town Egypt Jean-Léon Gérôme (1824-1904)

The picture has something of this: water, outdoors, architecture, daylight, military, seashore, recreation, sky, beach, landscape, castle, sand, river, sea, people, fortification, war, building.
Perhaps it’s a painting of a group of people riding on the backs of horses on a beach next to a body of water with a castle in the background.