Chicago River, 90-minute architecture tour, daytime, sunny weather, blue sky with few white clouds, modern skyscrapers, historic buildings, ornate bridges, sailboats and speedboats on the water, people taking photos on the riverwalk, walking, standing, pointing, gesturing, sunglasses, hats, casual clothing, jeans, t-shirts, sneakers, backpacks, cameras, binoculars, Chicago cityscape, urban landscape, stone walls, glass facades, steel beams, wooden docks, rippling water reflections, vibrant city life, dynamic composition, low-angle shot, warm natural light.