The group -- who maintained six feet of separation throughout the event -- was gathered to thank local volunteers and essential workers amid the ongoing COVID-19 pandemic.
The royal family enjoyed a performance by The Salvation Army UK band, before William and Kate greeted a number of essential workers from organizations and charities, all of whom will be working or volunteering to help others during the Christmas period.
The conclusion of the train tour comes ahead of the Christmas holiday, which will look different for the royal family this year. While the royals typically gather at their Sandringham Estate in Norfolk, England, for Christmas, COVID-19 has changed their plans.
"Having considered all the appropriate advice, the Queen and the Duke of Edinburgh have decided that this year they will spend Christmas quietly in Windsor," Buckingham Palace revealed in a statement earlier this month.
Where the rest of the royals will spend their holiday remains largely unclear. Hello! Magazine reports that Charles and Camilla will be at their Highgrove House in Gloucester, England, while a student in Cardiff told The Daily Mailthat William and Kate "still weren't 100 percent sure of what they were going to do or where they were going to be" after speaking to the couple.
Watch the video below for more on the royal family.