The correct answer to where is: In a biscuit tin buried beneath Windsor Castle.
It will air on BBC One in the United Kingdom on Sunday.
Royal commentator Alastair Bruce said the head has to be kept still when wearing it and the Queen agreed: "Yes".
Mr Bruce was able to "gently" nudge the Queen to elicit further insights which "worked very well" during the 90-minute encounter, which he described as a "conversation". Even though several of her family members seemed befuddled by Graham, his fiery preaching style piqued the queen's curiosity, and she asked for a private meeting with him. The trap door that led to the secret area still exists today.
The documentary "The Coronation" is part of the Royal Collection Season and will be screened in the United Kingdom on BBC One at 8pm local time on Sunday.
"You can't look down to read the speech, you've got to take the speech up, if you don't your neck would break, it would fall off", the Queen said referring to the annual ceremony of the opening of the British Parliament, and the state speech where she reads the Government's programme. "Once you put it on, it stays".
Prince of Persia creator is keen on resurrecting the franchise
Ubisoft Montreal - the studio which would most likely lead a new Prince of Persia title, says the series is still "on pause". The gameplay, moves and even wall climbing are similar characteristics that the protagonists from the two franchises embody.
In the hour-long program "The Coronation", Queen Elizabeth gives viewers her personal account of the memorable event that took place 65 years ago, sharing just what it was like to be in her shoes.
The keepers of the royal things were a little anxious about all the important crowns and stuff going missing or getting bombed during the second world war, hence the most important elements of the Crown Jewels were taken from their position in the Tower of London and hidden away.
"There are some disadvantages to crowns but, otherwise they are quite important things", the Queen added with a smile evocating her coronation on June 2, 1953, one year after her father King George VI died.
The Imperial State Crown was made for George VI's Coronation in 1937 and is set with 2,868 diamonds including 17 sapphires, 11 emeralds and hundreds of pearls, including four known as Queen Elizabeth I's earrings.
She claims it is so heavy that she has to keep her head lifted in fear of breaking her neck.