2013 25th Anniversary of Parliament House PNC. In 2013, Canberra's centenary year, Australia's Parliament House marks its 25th anniversary. Opened by Queen Elizabeth II on 9 May 1988, this architecturally and symbolically significant building is at the heart of our parliamentary democracy. Following an international design competition, New York based Mitchell/Giurgola and Thorp was awarded commission on 26 June 1980. Constructed almost entirely from Australian materials. the building covers some 250,000 square metres on a landscaped 32 hectare site. It houses more than 5000 people during sitting times and is home to an impressive art collection. The coin accompanying this cover focuses on the ordered aesthetic of this inspiring building, which can be seen in the background stamp, from the Road Trip Australia stamp issue. PNC also feature commemorative 20 cent coin.