Monaco's royal twins visit the Big Apple with mum Princess Charlene

Princess Charlene has shared a series of adorable photos from her recent holiday to New York City with her twins.

The royal, who is married to Monaco's Prince Albert, recently took Prince Jacques and Princess Gabriella to the Big Apple for the very first time.

It's unclear whether their dad joined them on their city adventure.

Ever the proud mum, Charlene posted photos from their holiday to her official Instagram account.

In the most recent post, she shared a picture of Jacques and Gabriella standing in front of the 9/11 Memorial Pools.

Charlene captioned the image, "Ground Zero" adding the American flag emoji and the prayer emoiji.

The children were dressed patriotically with Jacques wearing a stars and stripes beanie, while Gabriella's hat and coat was red, white and blue.

Earlier, Charlene had created a montage of their holiday photos set to the Jackson Five's ABC.

It shows the twins, who are 4, looking through a viewfinder on top of the Empire State building and walking the famous city 'sidewalks'.

The children were treated to a day at the Museum of Natural History where they took in the primates exhibition and saw a huge replica woolly mammoth.

They even got to meet Spiderman in the hallway of their hotel.

In December, the twins celebrated their birthday with a superhero-themed party at Monaco's royal palace. The royal family's private quarters were decked out with balloons, banners, party tables and streamers, all featuring the twins' favourite movie heroes including Superman, Batman and Frozen's Elsa and Anna.

There was a surprise in store for the birthday boy and girl when Monaco's Fire Department arrived with their cherry-picker. Jacques and Gabriella were allowed inside the cabin and given an aerial view of the palace courtyard.