2013 25th Anniversary of Australian Parliament House Commemorative Twenty Cent Uncirculated Coin. Opened in 1988 by Her Majesty Queen Elizabeth 2, Parliament house was designed by architecture firm Mtichell, Giurgola and Thorp whose winning design was selected from 329 entries from 28 various countries in a competition held in 1979. Parliament House was built into Capital Hill and not on top of it, symbolically placing parliament on the same level as the people it serves. Unlimited mintage. Please contact Adelaide Exchange Jewellers to find out more on this item.