The royals have been invited to ride the London Eye on Southbank, as part of their day of engagements held to mark World Mental Health Day on Monday 10 October.
William, Kate and Harry will be joined on the attraction by a group of people who will be sharing their mental health first aid experiences. The theme of this year's World Mental Health Day is the importance of "psychological and mental health first aid for all".
Prince Harry, Kate and Prince William will speak at a Heads Together reception
The Duke and Duchess of Cambridge and Prince Harry will start the day by attending a special Heads Together event at County Hall and the London Eye.
The royals will speak at a reception with the charities that are a part of the Heads Together campaign. They will also have a chance to meet with people who have received help from a relative, colleague or friend in crucial moments in their lives and the person who provided that support.
Photo booths will be set up, allowing guests to take a photo with a message thanking someone for being #Thereforme.
The royals will take a spin on the London Eye
William, Kate and Harry are particularly interested in hearing about the kind of support, such as professional services, that is available to people who may find themselves in a difficult situation.
Following the reception, the royals will take a spin on the London Eye.
Later that evening the structure will be lit up in purple in support of World Mental Health Day, joining other buildings around the world that will be doing the same and connecting Heads Together with the worldwide movement to end stigma around mental health.