Everything was going on as smooth as silk but on one day a green light shine on the humanity. All human beings got petrified by this green light. Years after later Taiju ( a character in anime) awakens and he found himself in a world full of statues. But he was not alone in this stone age , his friend Senku also awakened and then they found that they got petrified 3700 years ago.Now they will kickstart the new civilization with the the help of science and knowledge.As in my personal opinion this anime is great in the point of having a stone age and also gives some knowledge about science and stuff.
To watch this anime click on the link given below:-
anime talks 