In what year did the Australian National Gallery open

1982
The opening of the National Gallery in 1982 concluded a planning, design and construction period of fourteen years.

In 1968 the government announced a limited competition to establish an approach to the design of a national gallery in Canberra, inviting thirteen Australian architectural firms to submit proposals for a building to be completed in the early 1970s.

Read more...http://nga.gov.au/AboutUs/building/history.cfm