The ParalympicsGB dressage champion visited Royal Holloway, University of London (RHUL), to add the finishing touches to the Royal Mail postbox, the third in the area that has turned from red to gold in honour of the horse riding star's achievements.

The dressage star, who grew up in Sunningdale and studied a maths masters degree at the Egham University, has already had a post box in London Road, Sunningdale painted gold, as well as one in Maidenhead - where Sophie now lives - in the town's High Street. This is in recognition of her three gold medals in the team, individual and freestyle dressage events at London 2012.

As she arrived at the Egham Hill College, the London 2012 star was welcomed by a horde of flag-waving, cheering schoolchildren from both St Cuthbert's and St Jude's schools, who had been given time out of the classroom to see her.

Christiansen, said: "It's amazing to have a postbox painted gold at the place where I spent most of my academic life, it's incredible."

Asked how she felt about getting three gold medals in one Games, she replied: "Not sounding big-headed but I knew I was capable, but I did not want to make a big thing of it before I got there.

"In sport you never know what's going to happen, it's so unpredictable."

As Christiansen finished painting the postbox, RHUL principal Paul Layzell addressed the crowd to commend the alumna's achievement.

Speaking later, he said: "It's fantastic, and the first Paralympian in this round to get three gold medals as well, so we're pretty proud of her, particularly on the back of her success in both Beijing and Athens.

"She's also one of a group of Paralympians from RHUL, including Helene Raynsford the rower who competed in Beijing and Gaz Choudhry from this year's wheelchair basketball team, so we're very proud."