Halfway across the brand new bridge that links the two halves of Tintagel Castle, there’s a gap where you can look down at the waves crashing on the rocks below. Don’t worry; it’s only a few inches wide so there’s no danger of falling through it. But it’s a thrilling reminder that you’re suspended between an island and the mainland; between the present and the past.

Like a lot of places in Cornwall, Tintagel has a complicated history. It was a big settlement during the Dark Ages, bigger than London at the time, and very well connected with the lands around the Med. More Mediterranean pottery has been found here than anywhere else in Britain. Why was Tintagel so important? No one seems sure. Those Mediterranean sailors may have been coming for tin, but they could have found it elsewhere in Cornwall.

By the Middle Ages, Tintagel was a ruin, and it might have remained so if a medieval hack called Geoffrey of Monmouth hadn’t written a racy book called The History of the Kings of Britain. Some of the stuff he wrote was fairly accurate, but the bit about Tintagel was pretty fanciful. For some reason he decided it was the place where King Arthur was born, inspiring Richard of Cornwall (the younger brother of Henry III, and one of the richest men in England) to build a new castle on the site, straddling the narrow isthmus that linked the old settlement to the mainland.

For several centuries Richard’s castle was party central, a place for knights to enjoy some R’n’R, but then the isthmus collapsed and Tintagel became a ruin again, forgotten until Tennyson put it on the tourist trail. Sightseers came here in search of Camelot and though they only found a heap of rubble the location is spectacular, surrounded by jagged rocks and open water.

Before English Heritage built this footbridge you had to be quite fit to reach the part of the castle on the island (technically a promontory, not an island, but never mind). You had to clamber down the cliff and up again, along a steep and narrow staircase: perfectly safe, but tough going for kids and oldies. Now anyone can get across in a few minutes. I thought this modern bridge would be an eyesore but the graceful design is unobtrusive. By uniting the two sides of the castle it actually completes the view.

Originally the adjacent town was called Trevena, but when tourism took off it became known as Tintagel, after the castle. The town is full of gift shops hawking all sorts of Arthurian tat, closer to Monty Python and the Holy Grail than Excalibur. No matter. Even in Medieval times, Tintagel was a work of fiction. Like the bridge, these tacky souvenirs are part of its complex history — the story of how a real place became the location for a legend.

And despite the knick-knacks and the traffic jams, some of Tintagel’s old magic endures. As I walked up the hill towards the car park, past shops selling Cornish fudge and Cornish pasties, I stopped to catch my breath and looked back at the castle, silhouetted against the sky. Did King Arthur ever live here? Probably not. But this is still a special place, where an awful lot has happened. If only I believed in Merlin, I might like it even more.