The Sydney Opera House is opened by Elizabeth II after 14 years of construction.

The Sydney Opera House is a multi-venue performing arts centre in Sydney, New South Wales, Australia. Located on the foreshore of Sydney Harbour, it is widely regarded as one of the world's most famous and distinctive buildings, and a masterpiece of 20th-century architecture.

Elizabeth II was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until her death. She had been queen regnant of 32 sovereign states during her lifetime and was the monarch of 15 realms at her death. Her reign of 70 years and 214 days is the longest of any British monarch, the second-longest of any sovereign state, and the longest of any queen regnant in history.