Boston has seen plenty of monumental changes to its physical makeup over the centuries.

In just the 70 years since the end of World War II, reinvented neighborhoods, giant public-works projects, and ideas realized have altered the city seemingly forever. For better or worse.

West End razing

Beginning in the late 1950s, the Boston Redevelopment Authority and its bureaucratic predecessor oversaw the wholesale demolition of several acres of the West End and the displacement of thousands of residents, many of them long-timers, all in the name of urban renewal (which turned out to be far from renewing in many cases).

Developers, with official encouragement, then plunked high-rises in place of the West End's more intimate streets and lower-rise dwellings; and that was that: a neighborhood undone and cut off from the vibrancy of the rest of Boston. This result is slowly being undone.

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The High Spine

In the very early 1960s, an 11-member group of architects calling themselves the Committee on Civic Design sought to save Boston from the idea the powers that be were then batting around, which was: build high-rises throughout Back Bay and other low-rise areas of the city.

The solution? Build skyscrapers along a ribbon from Huntington Avenue to where Back Bay meets the South End. And so the high spine concept was born in Boston, preserving the character of various areas, but also remaking the skyline. The Pru was finished in 1964 and construction along the spine continues to this day.

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Combat Zone truce

The seedy adult-entertainment district once encompassed sizable portions of Downtown Crossing, Chinatown, and the Theater District. Dangerous and forbidding (or alluring, depending on one's tastes), the zone seemed a permanent fixture smackdab in the city streetscape.

Until the late 1980s, that is, when rising property values, stepped-up policing, and changing mores sent the Combat Zone into a terminal decline. By the early 1990s, the area was largely a historical footnote in Boston's history and has now been remade into the host of some of the city's bigger, pricier developments.

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The Big Dig

What MassDOT aptly described as "the largest, most complex, and technologically challenging highway project in the history of the United States" wrapped a decade ago, more or less.

The Big Dig left behind a sunken I-93; an extended I-90 all the way to Logan; two bridges over the Charles, including the Zakim; and 300 acres of open space, including the Rose Fitzgerald Kennedy Greenway.

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The Seaport's rise

One of the changes that the Big Dig helped spur was the rise in the desirability of the long-desolate Seaport area. Change was already underway when the highway project started easing travel there through the new Silver Line and the Interstate interchange.

To start, the feds relocated the Joseph Moakley United States Courthouse there in the late 1990s and hotels soon followed. And then, much more importantly, the convention center decamped to the Seaport from the Financial District in 2004, just when the Big Dig was starting to wrap. Things really began to take off. Here was a whole, expansive frontier for development, both residential and commercial (and retail). With water views!

Will the Seaport ever feel like a neighborhood like, say, the South End or Dorchester? Stay tuned. The only constant hereabouts sometimes is change.