The Thailand-Cambodia border runs 817 kilometres, from the tripoint with Laos in the northeast down to the Gulf of Thailand, and Hat Lek is where it finally reaches salt water - the southernmost permanent crossing on the whole line. The formalities on the Thai side belong to the Khlong Yai Immigration Checkpoint; on the Cambodian side, the post at Cham Yeam sits in Mondol Seima district of Koh Kong province. The line itself was drawn by a sequence of Franco-Siamese agreements between 1867 and 1907, negotiated in Paris and Bangkok by men who had, for the most part, never seen the Cardamom ridges they were partitioning. Along this stretch the frontier follows the mountains only a couple of kilometres inland of the coast, which is why the Thai territory here is a ribbon rather than a region.

Control the only exit and you can charge what you like, and at Hat Lek people have long done exactly that. Minibuses to Trat leave every forty-five minutes between six and six for around 140 baht, but only once eight passengers have accumulated. The cheaper option is the songthaew - a pickup with benches down the back - though that usually means changing at Ban Khlong Yai for 80 baht and paying another 20 for the last fifteen kilometres. At the border itself, fares get rigged: a fixer inflates the price, takes his cut, and passes the driver a fraction of what the passenger handed over. Travellers arriving from Cambodia have been strong-armed into 1,400-baht transfers to Trat. The advice that actually works is unglamorous. Walk away from the barrier. Go up the hill about 150 metres to the police checkpoint and negotiate there with a driver who gets to keep the fare.

The Cambodian side has its own established repertoire, and the trick is that most of it is theatre. There is a quarantine desk that will take your temperature, issue you an official-looking form and ask for anything from 20 to 400 baht; no such form is required at any later stage. The visa itself has a published price, and officials have habitually asked for more than that in dollars or baht, sometimes waving a document that vanishes the instant a phone camera comes out. The paperwork is genuinely simple and needs no help, whatever the man offering you a free form suggests. One detail is worth more than all the money: make sure the entry stamp lands on your departure form and not only in your passport, because without it you may be told to return to this crossing before you can leave the country by any other. An e-visa obtained in advance sidesteps most of the performance.

In 2025 the abstraction of a border became very concrete. Tension built along the frontier from late May; on 23 July a Thai soldier was wounded by a landmine, and within a day the two armies were shelling each other. Thailand sealed its land crossings. A ceasefire at the end of July held until December, when fighting resumed and ran until a further agreement was signed on 27 December. Dozens of soldiers died on each side and roughly a hundred civilians were killed; by the end of the year more than half a million people had been driven from their homes along the border. The ceasefire has held through 2026, alongside sporadic incidents and a great deal of mistrust. For the stallholders and drivers and money changers at Hat Lek, none of this is geopolitics. A closed gate is simply the end of the month's income, and whether it opens tomorrow is no longer a question anyone here gets to answer.