Prince Harry has met Africans living with Aids and TB on his gap year tour of Lesotho, Clarence House has said.
Harry spent part of his gap year in Australia as a "jackaroo"
The 19-year-old prince also followed a village doctor on his rounds to see how locals dealt with the diseases.
More than a third of people in Lesotho are thought to be living with HIV or Aids - making the south African country the world's worst for infection rates.
Harry has also helped build foundations for a new health clinic, completed a road bridge and dug trenches for crops.
The visit was one of a number Harry has undertaken since arriving in Lesotho nearly three weeks ago.
He also visited a home for traumatised children on the outskirts of the capital Maseru.
Details of the trip had until now been kept under wraps for security reasons.
Harry, whose recent visits to a string of London nightclubs attracted attention, told BBC News he was having "really good fun" learning about the Africans' culture and way of life.
"They are all very very happy with life, smiling the whole time," he added.
But the fun-loving prince also told BBC News he hoped his "fantastic" African adventure would help "people back in England" recognise Lesotho needed more aid.
A programme of projects and visits has been put together by Prince Seeiso - the younger brother of Lesotho's King Letsie III - who has invited Harry as his guest.
Harry, whose late mother Diana, Princess of Wales was known for her work with Aids sufferers, is spending eight weeks in the mountainous kingdom.
Working alongside him has been his close friend George Hill, whose mother Annie was a long-time friend of Princess Diana's.
Harry stayed on the Hill family ranch during a three-month stint in Australia last year while working as a jackaroo.