Souvenir of the Environs of Lake Nemi Jean-Baptiste-Camille Corot (1796-1875)

The picture has something of this: water, nature, reflection, sea, sun, underwater, landscape, light, ocean, lake, fair weather, outdoors, tree, river, dawn, sunset.
Perhaps it’s a painting of a river with trees in the foreground and a castle in the distance on the other side of the painting is a body of water.