Over the last few years I have returned to the border and explored it, finally treating it as place. I followed the borderline from end to end, mostly on foot, occasionally by canoe. It is almost invisible now, although always delineated by something: a river, a hedgerow or stonewall. The surrounding area is mostly farms, open heath and fir plantations. British and Irish cows moo at each other over low fences. The last military installations were removed more than 15 years ago, but I had the coordinates of where they’d stood. Arriving at these sites and examining the road surface, I would feel like an archaeologist of the recent past.

Usually the only indication that a steel tower had once been in a certain spot was that the road widened slightly, and then narrowed. Borderlanders sometimes park cars they’re selling in these lay-bys, with a sign propped up in the windshield giving the price, in euros or British pounds, and two cellphone numbers, one northern and one southern.

The borderland is a practical place. It carries some scars, but people are mostly just busy trying to draw advantages from what is usually a disadvantage: living on the periphery. New tourism initiatives encourage hikers to visit the border’s hill country, and I walked many stretches of unexpected beauty. Bridges have been built and roads reopened. There is still some smuggling, but it’s limited to diesel fuel and conducted by criminal gangs, not people like my father. Today’s open frontier means some Borderlanders live in the north but work in the south, or live in the south but send their children north to school. Life on the border still has complexities, but the canniness of my father and others has been replaced by something more unambiguous and legal, something more like the wisdom that comes from living with your feet in two cultures.