Chicago Athenaeum Museum, neoclassical architecture, grand staircase, ornate details, Ionic columns, symmetrical facade, rusticated base, granite walls, copper roofing, intricate moldings, stained glass ceiling, natural light pouring in, grand hall, sweeping arches, majestic chandeliers, marble floors, elegant benches, visitors admiring art, soft warm lighting, afternoon sun rays, subtle shadows, 3/4 composition, HDR.