Introduction to the outside and back: When designing the Oslo Opera House, designer Robert Greenwood first thought of not making it taller and bigger to attract the attention of the people in the city, but hoping to make the opera house a "for the people" 's square". He is very willing to see visitors walking along the sloping and spacious ramp to the 32-meter rooftop to enjoy the beautiful scenery of Oslo, watching them bask in the sun, skateboarding, and even have a picnic on it without any scruples.