The new play area has been modelled on famous British landmarks and is expected to open on April 12.
The woodland playground has replaced an existing smaller play area.
Phase one of its development has been completed which includes an array of impressive treehouses and walkways.
The Duke and Duchess of Cambridge have three children together – Prince George, seven, Princess Charlotte, five, and Prince Louis, two.
According to royal experts, Kate’s ‘legacy project’ has been her work in early years development.
Last year, the Duchess released the findings from her “Five Big Questions” survey which focused on the early years sector and under five-year-olds.
The survey collected views from half a million people in the UK for the study about raising children under the age of five.
In a statement, the report was labelled “a milestone moment” for the Duchess’ “work on the importance of early childhood in shaping the rest of our lives and broader societal outcomes”.