Miles Kington: Niagara is no match for Wales's national treasure

Even people from South Wales, where they couldn't care less about North Wales, would admit that Pistyll Rhaiadr is truly dramatic

I grew up on the Welsh borders, more or less where Shropshire and Cheshire meet, in a village called Gresford. Gresford had no great claim to fame, except that its church had a fine peal of bells which figured in a list of the Seven Wonders of Wales.

You have never heard of the Seven Wonders of Wales? I am not entirely surprised. Here they are, commemorated in rhyme by some anonymous 18th-century scribbler.

"Pistyll Rhaiadr and Wrexham steeple,

Snowdon's mountain without its people,

Overton yew trees, St Winifred's Well,

Llangollen Bridge and Gresford Bells."

You don't have to look at the list for very long before noticing that these wonders are not uniformly wondrous. Nor, indeed, are they truly representative of Wales, being mostly clustered in the north-east corner of the country. It is the sort of tentative list that they might have come up with at a meeting of the Denbighshire and District Tourist Board, wondering how they could attract more visitors, before discarding it, conscious that no modern traveller is going to stir far to see a yew tree or hear a bell.

Yet even people from South Wales, a part of the world where they couldn't care less about North Wales, would have to admit that two of the wonders are truly dramatic. Snowdon is a higher mountain than anything else in Wales, and higher than anything they have got in England, so it needs cherishing. And Pistyll Rhaiadr, or Rhaiadr Waterfall, is the tallest waterfall in Wales, if not in the British Isles.

My brother and I went to visit Pistyll Rhaiadr several times in our youth, it being about an hour's drive from home, and an impressive sight it is too. It lies at the end of a long upland track which leads to nothing much else but the waterfall and stops when it gets to it. There was a car park and a café and then the bottom of the falls, a long thin skein of water falling down from the top of the cliff a couple of hundred feet above you. I once approached it from the top, following this modest moorland stream across a modest moorland, until suddenly it fell away beneath my feet into nothingness, which, for someone like me, who doesn't like heights, was an impressively ghastly experience not be repeated.

I had not thought about Pistyll Rhaiadr for a long time until at the weekend I encountered Mavis Nicholson, a fellow contributor to The Oldie magazine. She lives near Pistyll Rhaiadr, and when I said I had known it in my youth, she said casually: "You know it's higher than Niagara Falls, don't you?"

I was staggered. I could not believe it. In fact, I did not believe it.

"Admittedly it's a bit thinner than Niagara," said Mavis graciously, "but it's still a lot taller."

I bet her five bob she was wrong. I have seen Niagara Falls in the watery flesh. They are huge. I looked it up on the internet. She was right. The waterfall at Rhaiadr is 240-feet high, and the tallest the falls get at Niagara is 167 feet. So in terms of sheer height, North Wales has something mightier than Canada/America.

It is a bit difficult to say if Pistyll Rhaiadr has any rivals in the rest of Britain because people measure their waterfalls according to their best feature. Hardraw Force in Wensleydale is the highest unbroken fall, they will say, meaning that the water does not hit anything on the way down, even though it does not fall as far as the Welsh falls.

Undoubtedly the highest waterfall in Britain is the 300-foot high waterfall inside Gaping Gill, but that is an underground waterfall, visible only to potholers and other madmen. Does that count as a proper waterfall?

There are also waterfalls in Scotland which, when the water is running properly, look quite impressive, but I am minded to think that Pistyll Rhaiadr should have the title of Britain's tallest full-time waterfall. Well, if I am to owe Mavis Nicholson five bob, I want to get my money's worth.