Not all of it (though all of it is pretty strange) but the most southerly length, dividing Spanish Huelva from Portugal's Algarve, each on a side of the Guadiana River.
To be specific - very specific - I'd nominate the 100m of gazpacho coloured waters swirling between the villages of Sanlcar de Guadiana (Spain), and Alcoutim (Portugal) as a sort of surreal frontier theme park. The Guadiana River is the important part of the equation - the name's Arabic derivation, wadi ana, gives an idea of the stretch of history around these parts, and the river has divided the two villages and the two countries for more than six centuries.
And never more so than for the 50-odd years from the Spanish Civil War until 1992, when the border was closed over a length of 70km. Two years after the Berlin Wall had fallen, and long after Spain and Portugal had joined together to shelter under the umbrella of the EEC, there were still military block houses studding the Portuguese bank, and Sanlcar was overshadowed by a paranoidly large garrison. Police boats patrolled the no-man's land of the river. Fishermen out in their boats, the boxy affairs with candy-stripe paint jobs, were meant to go only as far as ... where exactly? The centre line, in their hunt for mullet, eels and barbel?
To cross between Spain and Portugal legitimately in those days meant either going to the coast and taking the Ayamonte ferry, or travelling 30km up-stream to the bridge at Mertola. Only on a few, a very few, feast days were boats allowed to carry villagers from one side to the other.
Smuggling, of course, was rife. "Alcoutim," I was told proudly in the small tourist office, "is a village of smugglers." Coffee and leather boots and tobacco, but mainly coffee, flowed from Portugal to Spain and was carried off into Andalucia on mule trains. "Every woman who crossed to a fiesta in Sanlcar was ... ah ... pregnant," my informant pronounced, sipping his wine, "and, by a miracle, they all came back as slim as virgins."
He could think of few things that might have been smuggled back from Spain. "Bad winds, the hot ones from the east, and bad marriages, that's all we get from them."
He looked across the river to Sanlcar and I did the same. "Actually," he added, "there is one thing they have better than us - fiestas. They have better parties on the Spanish side."
I was staying on the Spanish side. My hosts, Rob and Sue, were among the founding members of a small foreign community. Like most of them, they arrived years back, in winter, looking for a safe mooring for their live-aboard boat. They got to know the locals and also noticed the number of small fincas - garden-farms and orchards - abandoned along the river. They managed to buy a river bank wilderness of apricots, figs, peaches and olives.
Accommodation for guests was simple. A large hammock heaped with Moroccan blankets swung in the cool shade of a bower made by the arched and ground- brushing branches of a giant fig. The pan-piping of orioles and bee-eaters began at dawn, but so diffidently that, along with the growing heat, all encouragement was to lounge and read or to flop into the river's barely cool waters. Only with dusk and the first "churrings" and broken-wing flights of the nightjars did the heat ease. It was the hour for opening bottles of wine, and digging out jars of home-grown olives and salted almonds. A time, even, for reciting poetry or picking up a mandola.
Heat and simplicity and few clothes, fresh foods for picnics and day- sails up the river: a paradise for the likes of you and me. But not so much of a paradise for the locals, who had nowhere else to go for their entertainment.
The bars of Sanlcar and Alcoutim were fundamentally different from each other. Sanlcar was glaring white - perhaps it really was hotter - and its four bars were resonant chambers of chrome and smoked glass and ceramic tiles. The noise of talking echoed within them like the staccato clatter of flamenco and was silenced only for the sacred hour of the siesta.
On the other side of the river they didn't bother with an official siesta - they just got up later, and fell back to tortoise speed in the middle of the day. The Portuguese cafes were picked out in soothing ochres and tobaccos and faded creams. Sardines and split chickens tanned slowly on beds of coals, whilst old men in plush caps and suede work boats murmured about grafting trees, and irrigating vegetable plots.
Both sides of the river, though, had one common interest: how to cross it. There is talk of EU money either to lease a car ferry or to build a bridge to join the two shores. Even with the border open for the past six years, transport was limited to a small Spanish boat with an outboard motor which puttered back and forth at uncertain times. But the elderly Portuguese ferryman had retired the week before my arrival - doddery and with failing eyesight he'd finally crashed into Spain at full speed, and it was agreed that a man who could not see a whole country was a liability on the river. Feelings on the bridge question were divided. Many, and especially on the Spanish side where the road to the village was a 15km dead-end, saw it as a way to mainline tourists into the economy. Others were more realistic, "... a ferry would be better hombre - to make travellers wait a while, so they take a little drink, spend some money, perhaps stay. But with a bridge and a highway, they'll fly over us like birds."
For a casual tourist like me, transport from one side of the river to the other was problematic. Rob had launched a small pram dinghy for me, and handed over a set of rickety oars. "It'll pay you to wait for the tide wherever you're going," he warned, "and I've given you an umbrella as well, so you can sail if you find the wind behind you." I felt like Mary Poppins meeting Swallows and Amazons, but once afloat I found that my small craft also acted as a crude time machine. When it was 1pm in Spain it was only 12 midday in Portugal; so if Manolo's shop in Sanlcar, with its piles of watermelons, its hunks of jamon and hanks of fishing line, had already closed I could row across to Alcoutim, turn the clocks back by an hour and still provision up.
Day after day, and especially night after night, I crossed and recrossed the Guadiana. A perfect evening would start with coffee and gossip in Alcoutim, often with Chico coining his own phrases of admiration, ("Ha ha! look at her ... Alexandra ... beautiful ... that girl's measured in millimetres") or watching the boys diving off the quay as the sun set behind us. Then the eastwards drift to Sanlcar to eat steaks of seared hake and sip glasses of tannin-sour wine before a zig-zag trip back across the current to drink whisky or dance tangos and salsa at the Kiosque, the terrace bar run by Michel, the French hell's angel and philosopher.
Like the other incomers, Michel tempered the local enthusiasm for grandiose tourist developments with warnings: "People come here because it's a dead- end, because it's quiet and slow, and because of the wildlife and the river. If you lose that what have you left? What exactly, tell me?"
Perhaps the river's best defence was itself. At the very top of the village square in Alcoutim, half way up the wall of a building, a plaque announced just how high the river had once flooded. Only the autumn before, the river had risen in anger again, in a rush of water that had swept away cars, trees, livestock and boats. Flotsam and jetsam still hung in the trees 10m above out heads.
"They'd put pontoons on both sides, that summer, so they could develop the river as a marina. There were tens of boats moored for the winter." Rob was recounting how he'd woken to find the river lapping at the veranda of his hilltop home. "My boat and everybody else's boat was gone. We picked up 'Tesse' out at sea, and for two days we were pulling yachts out of olive groves, and out of the trees." He liked the moral of the story. "We're all still counting the cost, and there's been no more talk of marinas this year, and there won't be many people wintering up the Guadiana either. We're safe from being overrun for a while longer."
One slack midday tide I waded into the Spanish shallows to swim to the opposite shore. In an Alcoutim bar I'd met a Dutch girl, Krista, who was determined on "an international swim, from country to country", and we had pledged a dual assault in tumblers of wine. Now we were keeping our word. Her friend, Bianca, rowed the boat as the two of us swam slowly across the current to Portugal.
At the centre point I trod water and looked back at the dazzlingly white houses of Sanlcar. A couple of farmers stood watching our slow progress across the Guadiana. Ahead in Alcoutim, a trio of fishermen had also stopped work to watch as we inched our way through the thick brown water. Both groups had the slow head-shaking incredulity of those faced with the insanity of foreigners. In this at least, Portugal and Spain, Alcoutim and Sanlcar, seemed united. The river continued to join and divide them.
make it to the border
There are many cheap charter flights to Faro in Portugal for access to Alcoutim on the Portuguese side. Public transport to Alcoutim is slow and difficult, using country buses from Faro or Lisbon. Public transport to Sanlcar is close to non-existent and a hire-car is essential.
WHERE TO STAY
In Alcoutim there is pension accommodation in the village at Christina and Louis's (Portugal-0936-441905), 4,500 escudos (pounds 15-16) per two person room. English spoken. A new hotel is due to open soon, with considerably higher rates. In Sanlcar there is pension accommodation with Hilary and Axel (Spain-0959-388081), 5,000pta (pounds 21) bed and breakfast for two people. English spoken.
Safari camp accommodation - hammocks and camp-style outdoor beds - are provided by Rob Huber and Sue Gale (fax: 00-34-959-388257; Lista de Correos, Sanlcar de Guadiana, Huelva, Spain). They also do breakfast, evening meals, day sails and river picnics. Boats are available for guests. Prices and details on request.
A passenger boat between Ayamonte and Mertola stops at Alcoutim. This runs most summer days. Canoes are available for hire in Alcoutim. Enquiries from the tourist office in Alcoutim.
Both the Rough Guide to Portugal and The Cadogan Guide to the Algarve deal generally with the area, but do not have much detail on the river itself.
Sanlcar de Guadiana seems to have been overlooked by all guide books to Spain. This is something in the two villages' favour.