On one side of a busy intersection—where Western Avenue meets North Harvard Street—sits the Bus Stop Pub and a small, crowded lot of cars at Herb Goodman’s Auto Sales, where a yellow smiley face forms the “o” in “Auto.”

Next door, rising above these local establishments and a trio of nearby gas stations, stands the light brown tile and curved glass facade of Harvard Business School’s Teele Hall.

Across the street is the municipal William F. Smith Playground, where two parents push strollers past a play structure with red slides. An older woman sits on a bench overlooking the community basketball courts and baseball diamond, with her back turned toward the Harvard building across the street.

This is 02134—the zip-code of Allston—that will define Harvard’s future as much as Cambridge 02138 defined its past.

Allston is Harvard’s new frontier across the Charles River, a diverse Boston neighborhood of busy streets, industrial buildings and mom-and-pop businesses where the University now owns 271 acres of land and is poised to shape a campus even larger than the one in Cambridge.

The University has owned and used land in Allston for more than a century—first the Soldiers Field athletic complex and later Harvard Business School.

But these self-contained parcels mark only the beginning of expansion into Allston. Deeper in the neighborhood, the University’s inroads are marked just by two thoroughfares bearing its name: North Harvard Street and Harvard Avenue.

The border between Harvard’s Allston and the old neighborhood is about to shift, and the contrast of Teele Hall and Herb Goodman’s is a sign of what is to come.

From Mass. Hall, where University President Lawrence H. Summers and his top deputies will decide the fate of Harvard’s Allston property, the land across the river is just a bus ride away. The number 66 bus departs from the island between Johnston Gate and the Cambridge Common and continues down JFK St., past the Kennedy School of Government and Eliot House and over the Anderson Bridge.

The bus makes its way across the river into Allston, once the site of a cattle market that supplied the Continental Army when it was based in Harvard Square during the Revolutionary War.

During this era, Allston was actually part of the City of Cambridge, as a neighborhood called Little Cambridge, but it seceded from the city in 1807 and later became part of Boston in 1874.

Now Cambridge’s most famous institution is considering further expansion into this former Cambridge neighborhood.

Rolling past Soldiers Field, past the red brick buildings of the Business School and towards Harvard’s prospects for the future, the number 66 bus reaches the corner of Western Ave. and North Harvard.

Looking east from there, industrial parks, warehouses, the major pharmaceutical firm Genzyme and railroad tracks sprawl toward the Charles River. Most of these buildings belong to Harvard, and they sit on one of the University’s largest single parcels of property in Allston.

In the other direction, a string of commercial developments—mainly car dealers and auto repair shops—stretches toward a shopping center with K-Mart, Star Market and other chain retailers. The shopping center is also on Harvard-owned land.