Members of the borough’s Brownies groups visited the Prime Minister to celebrate the organisation's 100th birthday.
The girls from 16th and 20th Harrow Brownies, and 3rd Stanmore Brownies were some of 100 from across the UK to visit David Cameron in Downing Street last week.
The visitors got the chance to show some of the activities they do including archery, giant games and plate spinning.
Mr Cameron said: “I’m delighted to be celebrating the Brownies’ 100th birthday in Downing Street.
“Being a Brownie is about having fun, being adventurous and learning a huge number of skills from cycling, to science experiments and crime prevention.
“But at the heart of what it is to be a Brownie, is the promise to give back and serve others. In this centenary year Brownies have been volunteering across the UK as part of the Big Brownie Birthday Badge Community Challenge.
“Happy 100th birthday and here’s to another great 100 years ahead.”
Leader Simi Gupta, who attended the party with the Brownies, added: “This was a once-in-a-lifetime opportunity for the girls.
“Once they got into the garden they really let themselves go and had a great time – by the end they were exhausted. We’ve really made the most out of this Big Brownie Birthday year, it’s been great.”