I’m strangely intrigued by international borders.  I think it’s because as a Brit, we don’t have any.  I don’t really understand why I can’t simply step over the imaginary line a few miles down the road, thus avoiding all the tedious formalities, but that aside, they intrigue me with their subtlety.  The scenery should be identical.  The vegetation remains the same.  Unlike in Britain, where crossing into a neighbouring state involves traversing either over or under a large body of water, there is no buffer zone to enable a distinct separation of cultures and therefore there should be no obvious difference.

There is, of course.

If heading from Singapore to Malaysia had felt like a bump-filled return to earth, Malaysia to Thailand was another rung down the reality ladder.  This time it was the Malaysian side which operated with brisk efficiency: not much to look at, certainly, but the queues moved quickly, with little room for confusion.

Once through Malaysian customs, we hopped back into the minivan which had taken us from Penang for a few minutes’ drive through no-mans-land before arrival at the Thai border.

Stereotypical South-East Asia hit me like a ton of bricks.

Here there were multiple queues snaking in and out of one another, no apparent rhyme or reason behind which was for what.  People sat, stood, waited in groups, and bunches of immigration cards were waved around with no further explanation nor obvious places to complete them.  I shared out my substantial collection of Korean pens and we leant against the minibus windows.

Eventually our driver – merrily darting between all sides with a charming grin in lieu of his own travel documents – pointed us through an unmarked gap to wait.  We ambled through, no questions asked, and found ourselves on the other side of immigration; passports stamped, granted, not that anyone stopped us to check.  Back in the bus, scattering dozens of people who’d been sitting on the ground in the “vehicle” lane, with bags unexamined and onward plans unquestioned, we arrived in Thailand.

Two minutes later we were back on the road where we were greeted with run-down buildings, fewer vehicles (one of which was a motorbike and side-car containing an entire hawker stall), everything written in Thai and emphatically no English, nor a single Roman character.  Our driver responded to this palpable change in governance by putting pedal to the metal and hurling the full-to-bursting van down the road at 80 mph; considerably faster than Malaysia’s highest speeds and on noticeably lower-quality roads.

We raced through the Thai countryside and a few towns for a couple of hours before reaching Hat Yai, where we were deposited outside a tour office by our maniac driver whose clutches we couldn’t escape fast enough.  A German couple, the only other foreigners on our bus, were heading on to Trang, as were we, but they didn’t have tickets; we had tickets, but there was no bus.  A grumbling employee threw all of our bags into the back of his sedan and then tried to make the four of us get in the back with the two giant rucksacks which wouldn’t fit in the boot.  We refused.  The bags came back out.  The Germans were abandoned to their fate and Peter and I, crumpled tickets in hand, were unceremoniously whisked away . . . not direct to Trang, as we had thought, but the local bus station.

After weeks of soft Malaysian and Singaporean inflections, we were thrown in the deep end with our driver’s thick Thai accent and broken English.  He spewed out his life story whilst irritably navigating Hat Yai’s backstreets; he was from Bangkok, his partner had abandoned him, his business had gone bust, he owed a lot of money, he used to sell cars, he’d escaped his creditors down to the south, those charlatans in Malaysia kept selling tickets to tourists and making promises without knowing the realities and costs of provisions in Thailand . . .

I kept expecting him to demand a tip or involvement in his business venture, but he seemingly just wanted to vent his deep frustration.

“In four year, Hat Yai become a tourist town and now everything is expensive,” he announced bitterly.  “Last week, I take motorcycle taxi.  I forget something at office, go back, collect, go home again.  The driver, he charge me 120 baht.  I say – I am not tourist!  I am Thai!  He say – it is same for everyone.  Same price.  I say, is not fair.  But he not care.”

I found myself thinking of all the times I had been angry at the difference in price for locals and tourists; the flagrant overcharging and discrimination.  Suddenly I was seeing it from the other side; not the sellers on the make, but the locals suffering the fallout.

“120 baht!  For a single journey!  And I only make 250 baht [£5] a day”, he added sadly.

The onward bus journey was less eventful but far prettier, skirting the jungle-clad edges of mountainous Khao Ya National Park, characteristically Thai limestone peaks rearing up dramatically on the horizon.  Finally, to Trang – then a tuktuk to the guesthouse – and we had arrived.

Trang is something of a jumping-off point for tourists on their way to the Andaman Islands, but the Lonely Planet suggests that it’s worthy of a few more days, and for once I’m in wholehearted agreement.  I’d visited Thailand twice before but only Bangkok, and suddenly I was seeing the side so often mentioned by avid fans of the country: the wide smiles, the leisurely pace, the unabashed friendliness and shy giggles.

The tiny backpacker area runs along a single road from the train station, but we were staying in a guesthouse out on the edge of town, modern and sparklingly clean, with such low doorways that Peter spent most of his time there ducking and the rest of it rubbing his head.

The distance to the centre, we figured, offered an unparalleled opportunity to explore the local area: so off we set on foot.  “We’ll just grab a tuktuk when we see one,” we figured.

This bright idea disintegrated pretty quickly when we realised how scorchingly hot it was, how used to air-con we had become, and how being slightly off the tourist trail means taxis don’t exist (literally, there are no car taxis in Trang), and tuktuks are few and far between.

Life is slow in southern Thailand, and even the promise of 100 baht from a couple of sweaty, desperate tourists isn’t enough to rouse a tuktuk driver from his midday siesta.

After 45 minutes dragging ourselves through face-melting temperatures, past temples, an uninspiring park, and local people gawping at us in amazement, but no tuktuks whatsoever, we fell like desert-dwellers upon an oasis into the first open café we encountered.  The staff of young women were beaming so much we thought their faces might split; tourists outside of the main drag really don’t exist.  With no English menu and our Thai limited, as ever, to “hello” and “thank you”, we mimed our way to two iced coffees and something to eat (please, we don’t care what), which arrived in the unexpected form of toast with strawberry jam.

Trang’s Saturday night market is the stuff of local legend but of course we arrived on Sunday so had to make do with the regular weeknight one.  It turned out to provide some of the best street food I’ve ever eaten so I don’t feel too aggrieved.  We wound our way through the endless stalls, every one selling something completely different, each speciality more deliciously tempting than the last.

Even stuffing my face as I went, I still ended up clutching reams of plastic bags containing grilled meats, tiny pancakes, stuff on sticks, things to dip, tantalising packets, wraps, kebabs, bite-sized morsels, juices, coconuts, biscuits, sausages, soups . . . and popcorn.

When it comes to food, my FOMO is particularly intense.  Besides, I’m firmly of the opinion that “If not now then when?” and so no new culinary experience was going to miss my beady eye.  Or mouth.

Whilst I was excitedly zig-zagging from one stall to the next, Peter was drawing glances – most admiring, some horrified – from all whose gazes fell upon him.  His height is a talking point even in the UK but in Asia it’s a source of genuine astonishment, not to mention actual pain.  Trang’s market was definitely not intended for anyone above 5’6” – even I had to duck under most awnings – but Peter was narrowly avoiding garottings at every turn.  And so, even as I protested that I still had room for another round of barbecued pork (and I did), Peter dragged me away from my spiritual home, satay sticks and chilli sauce tumbling from my pockets as we fled to more vertically-friendly climes.

Even though it was the unassuming town with its friendly inhabitants and unexplored nooks which held the attraction, we both agreed it would be madness to spend time next to the Andaman Sea without visiting the islands for which it is famous.  So we coughed up and joined a tour on an open-sided boat filled with Thai day-trippers.  Weekends are mayhem, our host at the guesthouse warned, but Wednesday would be ok; even so, the idyllic beaches were far from tranquil, with tourists from the island hotels meeting small boatloads of visitors on thin strips of pure white sand.

Thankfully it wasn’t remotely near the madness of Ha Long Bay, and even if time was, as ever, sorely limited (the problem with day trips is all the time it takes to get there), we were still able to marvel at the sheer existence of these obscenely beautiful beaches.

Buy your tickets now.  Go on, check Skyscanner.  I’ll wait.

One stop was outside a cave, where everyone was ordered off the side of the boat, dutifully lining up crocodile-style in the water next to a rope, clutching on to the person in front.  Peter decided to sit this one out, but I gamely leapt into the water, although since the instructions had been in Thai, I didn’t have a clue what we were doing.  (I was the last one in because everybody else had just jumped in wearing their clothes.  Like their actual normal clothes.  I was the only person who’d stripped off to reveal a swimming costume (not even a bikini!) and had to run back to nab a t-shirt off Peter to avoid confirming my status as token foreign hussy).

We slowly swam into the cave, pitch black and echoing with chatter and excited yelps from the people at the front.  Occasionally there was a gigantic crash of water off to the side, invisible in the total darkness, which sounded like the entrance to the mouth of hell, and probably was since it was the opening to an underwater cave which is frankly close enough.

“I wonder where we’re going?” I thought, and then “Is there a reason everyone wore clothes?” and then “If this were a horror film then I’d be the first one to get picked off, the only blonde and right at the back of the line” and then “HOLY SHIT WHAT TOUCHED MY FOOT”.

And then there was a glimmer of light and suddenly . . .

We emerged into an open-topped cave.

Morakot (Emerald) Cave, to be precise: a secret cavern, only accessible at low tide through the hidden tunnel, with a tiny secluded beach and crystal-clear water, hemmed in by vertical walls which resembled the mouth of a volcano, hung with plants and creepers.

It felt like a scene out of Robinson Crusoe, or The Land Before Time, apart from my fellow tourists and the handy information board.

In the olden days it was used by pirates to store their loot, so I went off for a quick bit of treasure-hunting behind the palm trees but sadly came away empty-handed.

It’s undeniably beautiful from any perspective, but I think I got particularly lucky by not knowing what to expect.  I imagine my reaction was similar to that of the first pirate when he (or she, I bet there were SOME lady pirates) ducked into the cave to escape some bunch of murderous enemies, kept backing up, and emerged into this glorious miniature world.

On our final day in town we found a café with good coffee and even better wifi, and I got chatting to Dear, whose family owned the place.  She was fascinating: well-travelled, multi-talented, hugely engaging, and with a background in tourism and an abiding love for Trang.  We discussed the pros and cons of tourism in countries like Thailand, and she explained the difficulties she had faced in attempting to get the local government to pull their weight in clearing up the town and its naturally stunning mainland beaches, ignored by tourists due to their filthy condition.  The politicians would invariably agree in principle, but fail to show up; put their name down, but only for the boasting credentials; pass the buck; accept damaging kickbacks in return for looking the other way; neglect to take responsibility for things they could actually improve.  This on top of the disastrous impact we tourists can have on the environment in the first place, whether knowingly or otherwise.

I do believe that sustainable tourism is possible but it’s depressing to realise just how many people have to be on board to make it happen.  Tourists who’ll be prepared to spend a little more for an ethical experience; the powers that be who’ll shell out in the first place and use their influence to ensure ethically sound results; locals who’ll abide by the rules and gain long-term instead of making a quick, short-lived buck.  We can all try to do our bit to pull our weight but there are so many interested parties that I do wonder whether we’ll ever make it happen.  In other countries, newer to the tourism game, governments are too greedy for a bit of the action, and tourists unwilling to sacrifice either their comfort or a few extra pounds.  Thailand, I fear, may be a lost cause, although with people like Dear taking an active stance, I hope I’ll be proved wrong.

After we had set the world to rights, Dear offered to help us get dinner.  She reeled off a list of possibilities, eventually narrowing it down to a single place just ten minutes’ walk from our guesthouse, which never saw tourists and as such whose owners wouldn’t understand a word of English.  What began as a casual enquiry ended with her calling the restaurant and placing an advance order, warning them of our arrival time, ensuring we tried local specialities and that Peter wouldn’t be spiced out of the market, negotiating a price, arranging a tuktuk, and waving us off on our way.

Of course, the meal was fantastic.  The table groaned under the weight of food we’d ordered but we like a challenge, and dug straight in with wild abandon.  Clearly the gods intended for us to eat well that day since it also transpired we had just enough money to pay; literally with two baht to spare.

From foodie Malaysia, Trang had been a hugely welcome introduction to the delights of Thai food, even if the south is famed for its intense heat (both on and off the plate).  But it was also an example of somewhere accessible and comfortable, yet inexplicably off the tourist trail.  I know people think South Thailand equals beaches, but there’s far more to discover.

And when I say “more”, I mean “food”.  (Ok, and people, and tranquillity, and tuktuks shaped like frogs).

I mean, beaches are nice and everything, but Trang’s barbecued pork?  That’s my idea of heaven.