an aesthetically detailed digital art image of a huge walled city with a beautiful river running through it, built into a cliff face of a mountain, ocean waves lapping its walls, by frank frazetta and alphonse mucha on artstation, oil on canvas, bright colors, art nouveau, epic composition, dungeons & dragons fantasy art, hd, god - rays, ray - tracing, crisp contour - lines, huhd - 8 k