Taking your child to the swimming pool for their first lessons is a big milestone for any parent, but it can be tricky to find a private location when you're a royal.
SEE: Inside Prince William and Prince Harry's childhood home with Princess Diana
The likes of Kate Middleton and Prince William would struggle to simply pop to local swimming lessons unnoticed, but they do have access to the Queen's impressive London home which means they don't have to.
The Duke and Duchess of Cambridge live at Apartment 1A in Kensington Palace, but reportedly visit Buckingham Palace's swimming pool – much like other members of the royal family have done for the past 80 years. See everything we know about where the royals swim…
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1. The building was originally a conservatory
Before being converted into a swimming pool, the building acted as a conservatory designed by architect John Nash.
2. The swimming pool was built as a surprise for the Queen
King George VI commissioned the pool in 1938 after he took the throne. He wanted to ensure the privacy of his daughters Princess Elizabeth and Princess Margaret, who had been having lessons at the Bath Club.
The pool was built for Princess Elizabeth and Princess Margaret (pictured in 1946)
According to a newspaper article in January 1939, the young Princesses returned from Balmoral to find the surprise swimming pool. "The surprise was a new swimming pool, which was specially constructed for the two little princesses so they may have their weekly swimming lessons next year at their own home," it read.
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3. The interiors are very practical
Unlike the luxury you would expect inside the palace walls, the swimming pool is actually built with practical materials.
A letter from Sir Philip Sassoon, from the Ministry of Works, to King George VI in 1938 when the pool was being designed requested that the walkway around the pool was to be made of vitreous mosaic tiles, rather than glazed as they are "less harsh in appearance and less slippery".
Buckingham Palace's pool is located in the North Wing
However, some thought did go into the aesthetic. He also suggested that the edges of the pool were to be marked in black, with two bands of green, one below the level of water and another at the bottom of the pool, to add "sparkle and liveliness to the water".
4. It survived World War II bombs
The pool house had only been completed for one year before it was bombed during World War II. On 10 September 1940, a bomb shattered all the windows in the North Wing of Buckingham Palace.
READ: The Queen's unseen secret rooms at Buckingham Palace
5. There are no photos of the interior
The pool is believed to be on the left-hand side of this photo
Pictures of the exterior show the building replicates that of the Roman baths, with concrete plinths, a vaulted ceiling and large glass windows. However, the interior remains just for the eyes of the royal family and special guests.
6. Many royals have learnt to swim at the pool
It is not only where the Queen and her sister Princess Margaret perfected their swimming technique, but also where Her Majesty's children Prince Charles, Princess Anne, Prince Andrew and Prince Edward all took their first strokes.
Kate Middleton has also taken her three children to learn to swim in the pool over the years – and we have no doubt it's a big hit with Prince George, Princess Charlotte and Prince Louis. Speaking to former world and Commonwealth champion James Hickman in 2014, Kate reportedly told James that George "loves the water and he grabs things to splash with".
The Duke and Duchess of Cambridge's eldest son supposedly loves the pool
7. Prince Charles invited his friends to sail model boats
Buckingham Palace's pool wasn't just a place to swim for Charles – he used the water to sail model boats and reportedly even invited his school friends to join.
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8. Prince Philip used it on a daily basis
The late Prince Philip supposedly used the swimming pool for his daily exercise when at the London residence with the Queen.
9. Prince Charles used to throw his kids into the pool
Princess Diana and Prince Charles' sons learnt to swim at Buckingham Palace
Prince Charles and the late Princess Diana also loved to have fun in the water with their kids. Both Prince William and Harry learnt to swim there, while Charles also revealed how he got William to love the water.
"I threw him in the swimming pool on occasions. Instead of putting him off, it enthused him," he admitted during an event at the British Sub-Aqua Club.
10. The private pool isn't just for the royal family
Members of the Staff Sports Club can also use the pool, provided it doesn't clash with one of the royals' swims.
"The rule is that if a staff member is swimming and one of the Royals appears, they have to get out, unless invited to remain, which often happens,’ Brian Hoey explained in his book, Not In Front of the Corgis: Secrets Of Life Behind The Royal Curtains.
"If when the staff member turns up a Royal is already in the pool, the servant, and this includes senior members such as the Private Secretary or Keeper of the Privy Purse, will not attempt to join them."
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