Kate Middleton's 2011 wedding gown was unforgettable, and designing it was just as memorable, according to one of the designers who created the dress.

Mandy Ewing, who was part of the team that created Middleton's Alexander McQueen wedding dress, recently opened up about the process and effort that went into the creation of the gown. The gown that the Duchess of Cambridge wore when she tied the knot with Prince William in 2011 was designed by Sarah Burton and her team, who kept it a secret until the wedding day.

"We knew who it was for, but it was very secret - we had net curtains up and cleaners were not allowed into the room and the code on the door was changed," Ewing told Hello!  "The dress was all in the news, but nobody knew who was doing it. When you're working you just focus on it and try not think about what's in the news. But it was an exciting event and everybody loved working on it - it was a once in a lifetime opportunity."

Middleton's wedding gown was once again brought to the spotlight after Camilla Parker-Bowles' visit to the Royal School of Needlework, where Ewing is one of the embroiderers, on Wednesday. The Duchess of Cornwall tried her hand at embroidering during the visit and joked that she would "leave it to the experts."

Middleton's wedding gown included intricate lace motifs. Aside from her wedding dress, Burton also designed the Duchess of Cambridge's shoes and veil.

"I loved making the dress, I loved adapting my ideas to suit the person and the occasion, and we put our hearts into it," Burton told New York Times Style magazine about the experience. "I respect the intimate nature of that lovely project and I respect the friendships that were forged during it... an instinctive, intelligent, imaginative young woman's wish for a beautiful wedding dress — or any kind of dress — is the most natural thing in the world."

Six years after Middleton and Prince William's royal wedding, the couple is expecting their third child together. However, this has not stopped them from fulfilling their royal duties. Next week, the Duke and Duchess of Cambridge will be attending the Royal Variety Performance.

Earlier this week, Prince William and Middleton had a fun and action-packed day when they visited the Land Rover company. The couple enjoyed off-roading and afterwards visited the Aston Villa Football Club.

What can you say about the level of secrecy and care that went into the creation of Middleton's wedding gown? Drop a comment below.