World Architecture Day, global celebration, UNESCO headquarters, Paris cityscape, sunny afternoon, blue sky with white clouds, iconic Eiffel Tower in background, modern skyscrapers, historic buildings, arches, columns, grand staircases, intricate facades, ornate details, vibrant street art, diverse people from different cultures, smiling faces, casual clothing, cameras, flags, banners, confetti, festive atmosphere, warm natural light, shallow depth of field.