I’ve already recommended Garrett Carr’s new book about Ireland’s border country, The Rule of the Land (Faber). From his website, I’ve discovered that Carr made a programme for Radio 4, Charting the Border, broadcast in 2014, in which he detailed some of the unofficial, unmapped crossings that he came across as he made his way from east to west. You can still listen to it on the BBC’s iPlayer.

Borders have been much on my mind lately — and not just because of an American president’s desire to wall himself off from Mexico. In July 1997 — nine months before the signing of the Good Friday Agreement — I set out to travel by train from County Derry, where I grew up, to Cork. I had to go from Belfast to Dundalk by bus: rail services had been suspended because a signal box had been blown up on the line. In October last year, on a new luxury train, the Belmond Grand Hibernian, I crossed the border twice and didn’t even register I’d done it. Ireland, post-Good Friday, is a healthier place. But what about post-Brexit? Will there be a “hard” border again? Will things get trickier for travellers? Those were questions raised by many strangers meeting on our train last October.

Kapka Kassabova, who was born in Bulgaria and now lives in the Scottish Highlands, has recently been travelling along the border zone “where Bulgaria, Greece and Turkey converge and diverge”,  a region she reports on in Border: A Journey to the Edge of Europe, which was published last week by Granta. In The Guardian at the weekend she wrote:

“It is understandable that borders are creeping into fashion again, lubricated by the passions of various new nationalisms that aren’t at all new – in the same way that, once in the system, viruses aren’t new, just dormant or rampant depending on the general health of the patient. It is understandable because there is an overwhelming sense of fear in many – and a border appears to be ‘a kind of solution’ (the Greek poet CP Cavafy’s ‘Waiting for the Barbarians’, from which this quote comes, is perennially fresh). But it may be useful to recall that, until 1990, for half of Europe’s people, borders were a trauma. The iron curtain was more than a figure of speech. It cut into flesh, into families, into the lives of the unborn.”

I’ve been sent a copy of Kassabova’s book (reviewed yesterday by Sara Wheeler in The Observer), but haven’t yet had a chance to read it. I have, though, read and reviewed a timely account of Ireland’s dividing zone, The Rule of the Land by Garrett Carr (Faber & Faber), which was also published last week. That review is due to appear in the travel section of The Daily Telegraph next weekend.

Carr’s is a marvellous book, in which he contends that Ireland is more divided than any of us suspected — not in two but in three: north, south and borderland. The third state has its own frontier-slipping people, who have their own language. They talk of dolmens — the prehistoric tombs that dot their territory — as “domees”; they say “fornenst” for next to, or up against. Or they will if you can get them to talk at all. For the borderlanders, Carr says, are a people whose conversational tone is always closing; “who say hello in a way that makes you aware it is also goodbye.”

Both Kassabova and Carr were among contributors to a discussion on Radio 3 of borders, led by Anne McElvoy, that was first broadcast last Thursday.

The temperature at the moment is 9°C where I am, in Epsom, Surrey, but I’m deep in Snow (Little Toller), a lovely little book by Marcus Sedgwick — who grew up in Kent but now lives in the French Alps — about the science, art and literature of snow, and about the way in which crystals of ice can transform the mundane into the magical. Snow was Book of the Week on Radio 4 last week, read by Jonathan Firth, and can still be heard on the BBC iPlayer.

Snow is one of the latest offerings from Little Toller, an independent publisher based in Dorset and dedicated to the best in nature writing. Another of its recent titles — which I’ve only had time to dip into but I’m sure I’m going to enjoy — is Arboreal, an anthology of new writing from woodlands across the British Isles, published in memory of the ecologist Oliver Rackham and with royalties going to the charity Common Ground. Dipping into it at random, I read a tremendous contribution by Paul Evans about winter trees as seen from the 7.46 from Shrewsbury to Crewe. It’s the kind of piece that makes you feel, on the one hand, that your own powers of observation are extremely limited and, on the other, that you should spend less time in 2017 jabbing at the keys of a mobile and more time looking out train windows.

The photographer Steve McCurry, whose “Afghan Girl” is one of the best-known images of the past century, talked to Mariella Frostrup yesterday for Radio 4’s Open Book. (Frostrup, in her introduction, refers to the Afghan girl’s having “piercing blue eyes”; they are indeed piercing, but they are green.)

In 40 years as a photographer, McCurry has travelled the world. In his latest collection of pictures, On Reading (Phaidon), he photographs people —  in more than 30 countries — being transported by turning pages. As Paul Theroux puts it in his introduction, “there is always something luminous in the face of a person in the act of reading.”

The Open Book episode is now available on the BBC iPlayer. McCurry’s contribution starts 19 minutes, 55 seconds in, after Frostrup’s interview with the Israeli novelist David Grossman.

The Irish novelist Colm Tóibín has had an enduring relationship with Barcelona. He first went there at the age of 20 in September 1975 — shortly before the death of Franco —  and stayed on for three years to teach English, returning 10 years later to write his love letter to the city, Homage to Barcelona. He has just been back again for a programme in the Radio 4 series Reimagining the City, broadcast this morning.

I thought I knew a bit about Barcelona (though it’s 15 years since I last spent much time there), but some of what he said was new to me, including his revelation that the revival of the old part owes much to an influx over the past 20 years of Pakistanis. The new arrivals, he says, have been welcomed by the Catalans, with whom they share a belief in hard work and intense family business.

The first part of Laura Barton’s 24 Hours of Sunset (see below) went out on Radio 4 on Thursday and can now be heard on iPlayer. The second part, which takes her from Sunset Strip out to the coast, will be aired next Thursday.

Earlier in the week on Radio 4, Start the Week, under the chairmanship of Amol Rajan, editor-at-large of The Independent, touched on both the physical landscape of the British Isles and the mental and moral one. The contributors were Nicholas Crane, whose new book is The Making of the British Landscape: From the Ice Age to the Present;  Madeleine Bunting, author of Love of Country: A Hebridean Journey; the historian David Olusoga, presenter of the new BBC2 series Black and British: A Forgotten History; and Imtiaz Dharker, who was part of a “Shore to Shore” tour from Falmouth to St Andrews by four female poets earlier this year.

There’s long been a kinship between poets and pints, says Jean Sprackland. It’s particularly strong in her case: she grew up in Burton-on-Trent, a town synonymous with brewing, and had a summer job in the maltings. In Gone for a Burton, on Radio 4 earlier this week, she led a lyrical tour of the trade and the town. In the process, she learnt a new explanation of the phrase she’s borrowed for her programme’s title…

A tweet yesterday from the writer Melissa Harrison pointed me to a Radio 4 programme I missed when it was first aired last month. It’s A Journey Through English, a celebration of the diversity of dialects and accents you hear as you take the longest continuous train journey in Britain: more than 600 miles from Aberdeen to Penzance. I particularly liked the contribution from a Scot who said that she had spoken English since she was a child, when “you had one tongue for the hoose, another tongue for the street, and another tongue for the school or the kirk”. It was a programme that, in more ways than one, made Britain seem a bigger place. The guard, having reeled off the 43 stations the train would call at in between, sounded as though he needed a lie-down before the journey had properly begun.

Busy clearing my desk for a trip to the Canadian Arctic, I forgot to mention in advance Radio 4’s series of 15-minute talks this week on the theme of “The River”. Then I heard a contribution at lunchtime from the Scottish poet Kathleen Jamie on being transported back to the Bronze Age on the Tay. The beauty of modern-day radio, of course, is that you can catch up online when it’s convenient using the BBC iPlayer. Four talks are already on the BBC site and the fifth, in which the wildlife sound recordist Chris Watson follows the North Tyne to the sea, will be broadcast tomorrow.

Again on rivers, there’s a lovely piece by Melisssa Harrison on Shreen Water, in Dorset, on the excellent Caught by the River website. There, too, I’m reminded of the Shorelines Literature Festival, coming up next month in the Port of Tilbury. Contributors will include Rachel Lichtenstein, whose Estuary: Out from London to the Sea is due out next month from Hamish Hamilton; Deborah Levy; Patrick Wright; and those two cargo-ship crew members Horatio Clare and Rose George.

Kathleeen Jamie, incidentally, was joint winner in 2013 of the Dolman Travel Book Award for Sightlines, an extract from which you can still read on Deskbound Traveller.