Kabage Karanja had one of his earliest and most profound experiences when, as a teenage member of Hodari Boys, a youth mentoring club, he camped in the Suswa Caves, northwest of Nairobi, Kenya.

It was a special memory for Mr. Karanja, now an architect, partly because “I remember waking up in the middle of the night,” he said, “and there was a Maasai warrior just standing there, watching us sleep.” Read more