The Queen addressed the United Nations for a second time in 2010, again in her capacity as Queen of all Commonwealth realms and Head of the Commonwealth. The UN Secretary General, Ban Ki-moon, introduced her as "an anchor for our age". During her visit to New York, which followed a tour of Canada, she officially opened a memorial garden for the British victims of the September 11 attacks. The Queen's visit to Australia in October 2011 her sixteenth visit since 1954 was called her "farewell tour" in the press because of her age.
When was Elizabeth's farewell visit to Australia? (If the question is unanswerable, say "unanswerable")
October 2011