Boston was established in 1630 at the edge of the Shawmut Peninsula, and the historic neighborhoods which were developed on this peninsula have become the heart of "Boston Proper."
However, the peninsula itself has been significantly expanded over the years using reclaimed land, and the neighborhoods themselves have changed through a combination of market forces, changing preferences, massive fires, and misguided urban renewal policy. And Boston itself has grown significantly by annexing other towns: the South End was once the southern end of the peninsula, but today it feels like the middle of Boston, given the annexation of Dorchester and Roxbury.
The North End might be considered the oldest neighborhood of Boston, established 1630, but with the exception of the buildings around North Square, very little survives from the 1600s or 1700s. Ditto for Downtown Crossing and the West End, which was an affluent and elegant neighborhood before it was demolished by urban renewal. Even though Beacon Hill did not begin to be developed until the 1790s, it is today perhaps the most uniformly intact historic neighborhood in Boston.
The neighborhoods of Boston Proper include Back Bay, Bay Village, Beacon Hill, Chinatown, Downtown Crossing, Fenway-Kenmore, Financial District, Government Center, Leather District, North End, South End, West End, and the Waterfront.