The oldest continuously fortified site of English origin in the US, it dominates southern Boston Harbor.
The fort started out as a crude camp in 1634. In 1701 the English built the first true fort, Castle William (giving
Castle Island its name). In March, 1776 the English decided to leave the area, burning the fort to the ground.
An American fort was rebuit on the site and called Fort Adams, and finally Fort Independence.