The wall art was based on the petroglyphs of Val Camonica here in Italy. A bit anachronistic, but whatever. :P
On a side note, it always makes my head spin to think of all the generations that came before us. For hundreds of thousands of years people have been living their lives, loving, dreaming, laughing, crying, and we don’t even know anything about their lives, names, cultures, languages and so on. It’s so easy to forget people in ancient times were just like us, and for the most part wanted nothing more than leading a happy life with their loved ones.