There is a neglected piece of Cambridge, at the foot of the BU Bridge, across the road from the old Ford assembly plant, that belongs to a mysterious flock of geese.

Not Canada geese. Those are everywhere, the strutting, self-appointed lords of the riverbank. Theirs is a passing reign. Soon their vees will point south again.

No, these are domestic geese, sturdy and white, with knobby orange bills. They descend from breeds of distant lands – the Emden from the North Sea, the Chinese, the Occitanian Toulouse – but domestication robbed them of their migratory instinct. Their wild cousins will leave them behind.

They inhabit a sloping patch bounded on one side by Memorial Drive and on the other by the Charles. The geese shelter under tall maple and oak trees. Train tracks cut between them at a diagonal, heading to a decaying steel bridge over the river. This is the Grand Junction Railroad, built before the Civil War and now mostly dormant.

A tarnished cast-iron fence runs along the sidewalk at the top of the slope. At some point the fence was itself fenced with chain-link. A listless curtain of safety mesh, draped over a pair of orange traffic barrels, blocks an opening at the corner. At the staircase a dozen yards away is open, you search for the sign that says “do not enter.” You can’t believe there isn’t one.