The Leinster and Ireland duo's trip to Ethiopia with GOAL is being sponsored by Bank of Ireland.
On Tuesday Leo and Ian turned their attention to GOAL's ChildSPACE project, which works closely with children working and living on the streets of Addis Ababa, Ethiopia's capital city.
As part of this, they visited GOAL's drop-in and rehabilitation centre, where the charity provide children with a range of services, including education, medical treatment, sport and recreation and shower and clothes-washing facilities.
They also learned how GOAL teaches the children new skills, find employment and, in some cases, reunite them with their family.
Leo, who has led Leinster to three Heineken Cup titles, said: "We had a really good day yesterday, although it was a very long day too. We flew in to the capital Addis Ababa at 7am, dropped our bags off and made our way to the GOAL offices.
"After a brief presentation, we set out to visit a drop-in and rehabilitation centre that forms part of a programme that GOAL runs for children who live and work on the streets of the city.
"It is interesting to see how the focus has moved from 'giving aid' and is now centred much more on development and enabling the children to support themselves.
"We also had the chance to talk to some of the kids and it was really interesting to hear about some of the issues that they face on the streets on a daily basis, especially the girls with young children, who are usually the most vulnerable."
Ian, the 24-year-old out-half who made his first two starts for Ireland against the USA and Canada last month, is also writing a blog about his experiences with GOAL in Ethiopia.
"The staff showed us around the ChildSPACE drop-in centre, and then myself and Leo played a few games with the kids, such as football and table tennis, and obviously a bit of rugby, which was great fun," explained Madigan.
"The kids didn't have a clue who we were, but they seemed very excited to have so-called 'special guests'. They loved Leo especially - I don't think they had seen such a tall white person before!
"Addis is a massive city, with a fascinating history. There are so many street children in this city alone; about 60,000, I'm told, but GOAL is definitely making a difference in the areas where they work.
"I think GOAL really gets the balance right. The ChildSPACE project doesn't feed the children; it gives them the means to feed themselves by giving them skills for a future career and ambition to get off the street.
"It helps them learn a trade like metalwork or carpentry, for example and the income they can earn from this would be much higher than they would have been able to bring in on the street."
Leo and Ian travelled to a refugee camp in south-western Ethiopia today where GOAL runs a programme for some of the thousands of families who have been forced to leave their homes in Somalia because of drought and conflict.
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To read more about Leo and Ian's visit and GOAL's work in Ethiopia, click here.