Sydney Opera House: Funnily, the model of this structure originated from an orange peel which Jorn Utzon designed. His visions were critically challenged by the architects of his time but to this date, the Opera house is now a worldwide icon despite its construction difficulties due to its unique shape. It boasts 1000 rooms, 5 theatres, 5 rehearsal studios, 2 main halls and multiple restaurants and bars, a truely wonderful display of radical architecture