>> there are loads of these. this is what this area is. the cradle. it's called a cradle. now a world heritage site. because 60% of all the evidence for human evolution comes out of the valley. it's from caves like this that keep the record. that geology just conspires to preserve fossils. they're very, very rare things. but they're found more here in the last ten years than they're found anywhere. so you're home. this is where you started. >> this is my ancestral homeland? >> this is your ancestral homeland. ♪ >> that sound makes me happy. what does that sound remind you of, guys? what does that evoke for you, that sound? primeval. your enemy's genitals frying in hot oil? nothing? >> i get to work on the heart. something i strongly suspect