So when my wife and I were in the lovely old cathedral city of Wells, wondering what to do in place of a rather dull itinerary, it came as a revelation to discover that we were only a couple of hours' drive from the spot where the poem was inspired and written.
Somerset Tourism's booklet Famous Somerset reminded us that in 1796 Coleridge and wife Sara moved to the small village of Nether Stowey at the foot of the Quantock Hills. He was "inspired to write Kubla Khan after walking from Porlock to the tiny church at Culbone" and then having "an opium-induced dream".
We, too, were inspired, and abandoning a pre-paid night of accommodation we drove to Porlock, which turned out to be a charming village on the Somerset coast.
On the way we called at Nether Stowey, where the Coleridge Cottage is opposite a pub called The Ancient Mariner - after another of his great poems - but, as often seems to be the case with National Trust properties, it was closed for renovations.
But that didn't matter because, according to our booklet, the poetic dream didn't come to Coleridge in Nether Stowey but "whilst staying at nearby Ash Farm. On waking he managed to remember and write down just a few lines before being interrupted by 'a man from Porlock'."
Carrying on to Porlock, we quickly found ourselves a place to stay and got directions from the landlord on how to find the path to Culbone, as the place with the small church is now called.
Ideally we would have started our walk at Porlock Weir, a picturesque cluster of thatched cottages alongside a small harbour dating back 2000 years, but our landlord thought we might run out of daylight.
So instead we negotiated a maze of narrow lanes to the tiny hamlet of Worthy, start point of an ancient toll road, where for £2 ($3.40) you can use the toll road as a shortcut to the A39 or safely park your car beside an entrance to the South West Coast Path.
That might sound a steep fee for parking on a quiet country lane, but as a bonus the toll booth is one of the loveliest buildings I've seen - a brownstone thatched cottage with two gated arches, one giving access to the toll road, the other to the path - all surrounded by bright gardens and framed by the endless green of Yearnor Wood.
The path to Culbone is also like something out of a fairy tale, winding its way through ancient oaks and rare whitebeams, busy with grey squirrels and fine fat pheasants.
Every so often there were breaks in the green canopy, probably caused by the death of some aged giant, allowing the sun to shine through into some elven dell.
It was easy to see from whence Coleridge drew the inspiration for:
And there were gardens bright with sinuous rills,
Where blossomed many an incense-bearing tree;
And here were forests ancient as the hills,
Enfolding sunny spots of greenery.
Adding to the fascination of the walk were the many mysterious stone constructions, including walls, a stone chair where it was easy to imagine Coleridge sitting in contemplation, steps, paths, tunnels and bridges, seemingly in the middle of nowhere.
Could this stonework lining the route of his walk have prompted Coleridge to write that the grounds of his imagined pleasure garden "with walls and towers were girdled round"?
We later learned from our knowledgeable landlord that the stonework was part of a fantasy realm built for Lady Ada Lovelace - daughter of another poet, Lord Byron - who lived in the now-ruined Ashley Coome Manor.
Not all of the inspiration for the poem comes from the Porlock area. The "caverns measureless to man" were probably at Wookey Hole near Wells, where the mildly interesting caves open to the public lead through a succession of watery passages to dozens more caverns that are progressively being explored by cave divers.
Cheddar Gorge, which we drove through during our dash from Wells to Porlock, might well be Coleridge's "deep romantic chasm which slanted down the green hill athwart a cedarn cover".
But most of the images do seem to have had their origin in the magical realm we were walking through and suddenly, below us through the trees, we saw the focal point of the whole creation, the tiny Church of St Beuno in Culbone. This was the goal of Coleridge's journey, and of ours, and it is a truly magical spot.
St Beuno's is the smallest complete parish church in England - with a pump organ, a complete peal of bells and kerosene lamp lighting - and it is a miniature architectural gem. It is made all the more extraordinary by the fact that it is pretty much accessible only on foot, surrounded by trees, though you can see two houses through the woods.
Archaeological finds indicate it has been a place of worship of one god or another for perhaps 4000 years. The earliest Christian remains are from the 6th century - when the church's patron saint St Beuno brought the Christian message from Wales to this part of England - and the church is thought to be 1000 years old.
Many people have written about its spiritual atmosphere, and Coleridge indicated that it was from Culbone that he drew the mystical atmosphere for his poem.
St Beuno's does sit in a deep valley, with a stream rushing alongside its small graveyard, so perhaps it was there he was thinking of when he wrote of:
A savage place! as holy and enchanted
As e'er beneath a waning moon was haunted
By woman wailing for her demon lover!
Not that Culbone seemed a savage place to us - on the contrary, it was lovely and restful - but we did cut short our visit to be sure of getting back to Worthy and civilisation before nightfall.
In the darkness of a waning moon, that deep, lonely valley might be a very different place.
Haunting coastline
Another of Samuel Taylor Coleridge's great poems, The Rime of the Ancient Mariner, also draws its inspiration from the Somerset coast.
The story was apparently drawn from a neighbour's nightmare about a spectre ship, and the place from which the mariner set out on his ill-fated voyage and returned to tell the tragic tale is the nearby port of Watchet.
We didn't have time to visit Watchet, though the pictures indicate it's still a charming coastal town. But in many of the other ports that we did visit along the southwest coast of England - places like Porlock Weir, Minehead, Bostcastle and Padstow - it was all to easy to imagine a sepulchral figure halting a tourist to deliver its warning message: "There was a ship ..."
CHECKLIST
Getting there: Emirates flies three times daily from Auckland to Dubai, with direct connections to its daily services from Dubai to six airports in the United Kingdom: London-Heathrow, London-Gatwick, Manchester, Birmingham, Newcastle and Glasgow. Currently, fares to the United Kingdom are from $2925 return (inclusive of all taxes).
Where to stay: See porlock.co.uk.
Coleridge: For more information on Coleridge Cottage see nationaltrust.org.uk.
There's an informative article and map about the Culbone walk here.
Further information: For more about visiting the UK see visitbritain.com.
Jim Eagles visited Porlock with help from Emirates and Visit Britain.
