The Real 'Crown' : 5 Things to Know About Queen Elizabeth's 3-lb. Crown (and Its 317-Carat Diamond!)

Royal fans may be excited about Netflix’s series, The Crown, but what about the formidable piece of royal hardware that is the centerpiece of the show’s first season?

The coronation of Queen Elizabeth — which took place 64 years ago today — featured the famous 3-lb. Imperial State Crown, which is the same sparkler that the 91-year-old monarch wears when she attends the Opening of Parliament Ceremony every year.

Here’s what you need to know about the stunning piece of history:

1. It is 177 years old.

Probably the Queen’s best known crown, it was originally made for Queen Victoria’s coronation in 1838 by Rundell, Bridge & Co., then the crown jewelers. An earlier version of the crown – weighing a whopping 7 lbs., 6 oz. – was destroyed under Oliver Cromwell in the mid-17th century, who ordered the abolition of the monarchy and the sale of the crown jewels.

2. It is kept under lock and key at the Tower of London.

The crown is normally kept under ultra-monitored guard at the Tower of London, where it is a centerpiece of the Crown Jewels exhibit popular with tourists. When it heads to the palace to be worn by the Queen at the opening of the parliamentary session once a year, keepers leave a note to visitors saying it is in use.

‘Queen Elizabeth II Surpasses Queen Victoria’s Record Long Reign

3. It contains the world’s fourth-largest polished diamond.

Nestled in the “brow” of the crown – just below the breathtaking Black Prince’s Ruby set in the central panel – is the huge Cullinan Diamond, which was found in Africa in 1905, weighing 3,601 carats. (Yes, you read that right.) The stone was later cut into several pieces, with the “Cullinan II” earning a spot in the Imperial State Crown. (At 317.4 carats, it’s the fourth-largest polished diamond in the world.) For extra sparkle, the crown is also decorated with four rubies, 11 emeralds, 17 sapphires, 277 pearls and more than 3,000 smaller diamonds.

• Want to keep up with the latest royals coverage? Click here to subscribe to the Royals Newsletter.

4. It weighs as much as two Chipotle burritos.

The Queen’s biographer, Robert Lacey, confirms that the monarch finds it heavy – despite the fact that it is less than half the weight of the St. Edward s crown. The latter is the “true” coronation crown, but at more than 4 lbs., it is so heavy that she only wore it for a short time during her 1953 coronation. Instead, she slipped on the Imperial State Crown for her departure from Westminster Abbey and the journey back to the palace.

5. It got a makeover.

To make it more comfortable for the then-27-year-old monarch’s coronation, the crown underwent a redesign: The arches were lowered, making it lighter and “feminizing” it, as an insider tells PEOPLE.