The Duchess of Cambridge as you've never seen her before

The Duchess of Cambridge joined husband Prince William for a royal tour of Sunderland in the UK's north east.

After sitting out the Duke of Cambridge's visit to the Triumph motorcycle factory, Kate Middleton got adventurous in a different way on the royal walkabout.

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Arriving in her usual style, it wasn't long before the expectant mother-of-two had everybody gasping as she happily got a tattoo on her hand.

Visiting the local arts hub called The Fire Station Sunderland, Kate allowed the youth to apply a henna tattoo on the base of her hand.

WATCH: Students line up to hug the Duchess of Cambridge. (Post continues.) 

The 36-year-old seemed to giggle as the all-natural product was applied and asked questions of the young people sitting before her.

Kate was also seen chatting to young children, sharing a hearty laugh with them.

The Duchess, who is seven months pregnant, later donned a high viz vest over her custom jade coloured Dolce & Gabbana.

Dutifully, the 36-year-old tied her locks back into a ponytail as she and Prince William popped on white hard-hats and protective glasses as they inspected work on the Northern Spire Bridge.

The Duke even tightened one of the bolts on the new bridge, due to open in Spring - the tallest structure in North East England - which will connect the Port of Sunderland and the city centre, going over the River Wear.