Queen Elizabeth II left a ‘secret’ letter that will stay unopened until 2085

The mysterious letter resides in a building in Sydney

Queen Elizabeth II may no longer be with us, but we could still hear new words of wisdom from her in the future.

This is because the late monarch, who died on Thursday (8 September), left a secret letter to the citizens of Sydney that cannot be opened until 2085.

The Queen passed away “peacefully” in Balmoral Castle at the age of 96, after 70 years on the throne.

As head of state of Australia, she wrote a letter that has been hidden in a time capsule in a building dedicated to her great-great grandmother, Queen Victoria.

To celebrate the restoration of the Queen Victoria Building in 1986, the late monarch addressed the mysterious letter to the Lord Mayor of Sydney.

According to News.com.au, instructions on the letter read: “On a suitable day to be selected by you in the year 2085AD, would you please open this envelope and convey to the citizens of Sydney my message to them.”

The letter, signed simply “Elizabeth”, has been kept in a glass case in a restricted part of the building since the Queen penned it.

Reports say that not even the Queen’s personal staff knows the contents of the letter.

The Queen Victoria Building was first built in 1898 to celebrate her diamond jubilee. It was nearly demolished in the 1950s to be make way for a car park, but a bid to restore the building won out.

Queen Elizabeth II signs the visitor's book at Parliament House in Canberra 27 March 2000 as Australian Prime Minister John Howard stands in the background (NEWS LTD POOL/AFP via Getty Imag)

Now that the Queen has passed, King Charles III is Britain’s new monarch and the head of state of 15 Commonwealth realms, including Australia, New Zealand, Canada, and some Caribbean nations.

Australian prime minister Anthony Albanese declared that the country will get a bank holiday on Thursday 22 September to mourn the death of the Queen.

It will officially be called the National Day of Mourning for Her Majesty the Queen and will take place after her funeral, which falls on Monday 19 September.

This is because Albanese and governor-general David Hurley will be in the UK to attend the funeral and will return home on Wednesday 21 September.

Follow the latest updates following the death of Queen Elizabeth II here