On his return yesterday, he took the easy way up (in his parents' car) where he was genuinely surprised again, to see a plaque had been laid in stone at the top, recognising his achievement.
"I was not expecting that. I knew something was going on - my parents were talking secretively all the time, but I did not expect a plaque to be up here with my name on it.''
The 11-year-old make it up the Dunedin street on January 26, in about 10 minutes - without stopping. And in the process he raised more than $11,000 for Ronald McDonald House in Christchurch.
Harry said the organisation was close to his heart because it provided his family with support and "a home away from home'' when his sister, Darcie, was receiving cancer treatment in Christchurch last year.
Having the family stay together and visit Darcie in hospital regularly played a major part in her recovery.
Ronald McDonald House South Island chief executive officer Mandy Kennedy, of Christchurch, was there to help Harry celebrate the surprise unveiling.
"We are incredibly grateful and somewhat overwhelmed as well. It's a huge achievement in the first place, for a young man to even think of giving back in this way.
"What he did was so incredibly unique and shows the true character of a very lovely young man.''
There was a mixture of surprise and delight when she was told Harry had raised more than $11,000 for the organisation.
"That's enough to support a family at Ronald McDonald House for about 11 weeks. It costs around $1000 per week to take care of a family at our Christchurch house.
"Harry can truly understand what true value that has for a family because he's experienced it first hand.''
Many have tried to climb Baldwin St in weird and wonderful ways, including on stilts, rollerblades and a penny-farthing.
Harry's achievement is now recorded in history by the plaque, alongside that of Iain Clark, who roller-skated up Baldwin St in February 1988.
