The Boston Massacre was an incident just prior to the start of the Revolutionary War. British troops were stationed in Boston to enforce some new British laws and taxes that the citizens found undesirable.
A large crowd gathered around around a squad of British troops in front of the Old State House on King Street (now called Stat Street). The troops felt threatened, thought they heard “fire” and so opened fire on the crowd.
The site of the Boston Massacre is now a traffic island sitting in front of the Old State House.
You can find out more about the Boston Massacre at the website for the Boston Massacre Historical Society. The history is much more interesting than staring at the traffic island. Certainly, it was that historical significance that got it on the list of 1,000 Great Places in Massachusetts.