250 BC is when I'd pick to time-travel to. Ashoka was turning into one of the most famous emperors of India and Archimedes was growing into one of the greatest mathematicians of all time.
Parallel Lives is a beautiful visualization by Jan Willem Tulp that shows who lived when, showing overlaps, and sized by their prevalence on Wikipedia. I'm a history fan and have spent several hours scrolling through the site:
https://lnkd.in/g_hY86uR