natalia zaremba did not like the measure of it.ed her husband, the father of her two boys. was this risk foolish? >> why do you put them on this dam? >> we put them on this dam because we want them to confront discomfort. we want them to confront their fears. >> reporter: nathan schmidt co-founded the mountain seed foundation charity. we met in the 700 square mile park where the dam, finished after world war ii, is a tourist attraction for rock climbers. >> what makes this safe in your view? >> first off, we have professional mountain guides. the second thing is all of the equipment that we have, they train throughout the week on it. they know how to use the equipment. and then particularly the little children, they are also short-roped into a guide. so there's multiple layers of security for them. >> reporter: and so with all that security, the challenge was not so much under their feet as under their skin. >> help me. >> and here we go. >> reporter: myroslav kupchenkov, who told us his late father never went back, always forward,