There was always a good reason to get off the marked roads, never such a good one to get back on. The lanes made a series of processional ways that pulled us on, through green tunnels of vines trained on wires that stretched right over the road.
The trip was no more than a toe-in-the-water dip: we dashed to Porto with pockets full of air miles, a car-hire voucher left over from a Hertz mess in Turkey, and a map that showed a pleasing amount of empty space in the Parque Nacional da Peneda-Geres, where the top right-hand corner of Portugal bumps into Spain.
There is a fast motorway (A3) that gets you north of Porto in a flash. We were heading for the Pousada de S Bento, one of a number of traditional properties which are now state run and provide accommodation for travellers. This pousada sits on the side of a mountain overlooking the string of lakes backed up behind the Canicada dam, on the southern border of the national park. The scenery and the chalet buildings give you the uneasy feeling that you have strayed on to the set of The Sound of Music. It only wants Julie Andrews tra-la-la-la-ing round a corner for the picture to be complete. We needed copious quantities of vinho verde to convince ourselves that we were in the right country.
This is not the Portugal of the Algarve. It is green. It is cool. The people seem to have more affinity with Celts than Latins. There are the same forests of eucalyptus that you find in the south, but no orange groves. Maize grows in the minute fields scooped out of the mountain slopes, the cobs stored in small, narrow granary buildings raised on stone staddles. They look like boats marooned at low tide.
The best walk we had was centred round the village of Cabril, off the main road between Braga and Chaves. We abandoned the car on a dirt track and walked to Pincaes, a hamlet 1,600ft up in the mountains. Beyond the church, a footpath led down through white-flowered cistus and brilliant blue leptospermum towards Cabril.
We took the left fork before Cabril to Sta Ana, where the track wanders through a hamlet of tough small houses, built from vast blocks of grainy quartz. Butterflies wandered drunkenly over meadows of wild flowers. We were never away from the sound of water: cisterns gurgling in small farmyards, streams rushing down from the mountains to join the massive catchments below.
Though the landscape here was Englishly green, there were plenty of signs that we were not at home: long thin boat-shaped carts and tall narrow haystacks built around the tree trunks. Wood stacks were thatched with witches' hats of straw. So were the simple beehives, made from rounds of hollowed-out tree trunk. The long view was of mountains, the pines on the upper slopes petering out into a landscape of scrub, heather and huge smooth boulders.
Beyond Sta Ana, we took a track which dropped down to a river crossing. On the other side of the river was a tiny stone mill, roofed in red tiles. Water, channelled from a stream behind, shot through on to a wooden wheel mounted flat on the floor of the building. The water hit a ring of cups mounted on the rim of the wheel and spun it round. The whirling spindle drove the mill stone above, and a wooden hopper mounted over the upper stone gently jiggled grains of maize into the grinding space between the stones.
The building, no more than 6ft by 8ft, illustrated one of the odd facets of the Minho region. No communal effort. Every man his own mill. Every man his own granary.
The farmer grinding the maize smiled and nodded whenever we looked up from the hypnotic workings of the mill as though he was indulging two children on a birthday treat. He had two liver-and-white spaniels with him, lightly built but sporting, the sort of dogs you see in 17th-century portraits of English gentry.
Covered in the fine, creamy maize flour that coated the mill like pollen, we walked on through Chaos, had good strong coffee in Cavalos, and came to Cabril, where you see the old stone bridge of the village sunk beneath the waters of a dammed-up lake.
To get back to the car we had to retrace our route back through Pincaes. If we had had a decent map of the national park we could have found another way. We went to the national park office in Geres specifically to buy one, but the scale of the only one on offer was hopeless for walkers and showed only roads. With giant symbols, the map enthusiastically marked the location of summer settlements, wolf traps, Roman remains and prehistoric hill forts - but not how to get to them.
The national park office in Geres is at the top of the main street, above the colonnaded semi-circle of the spa. Like other old spa towns in the area, Geres is almost submerged by its past grandeur. It reeks of lost youth, lost chances. If you are not feeling too much that way yourself, it is quite pleasant to wallow in this Thomas Mannish melancholy.
If we had not gone to Geres, we would have missed the wedding and the home-made rockets that three old men were letting off at the side of the road in celebration. Cathartic explosions echoed around the bowl of hills. The men stood wreathed in smoke on the narrow verge, one picking up a rocket from a pile and handing it to the next who lit it and handed it to the third man, who stuck the 6ft-long stick between his knees and, with his hands clasped just below the fizzing touch paper, launched the beast out over the green valley. 'They lose a lot of hands that way,' said the laconic Portuguese man in whose house we stayed that night.
Though the pousada was perfectly good, it was not a patch on the Turismo de Habitacao houses that we stayed in on all the other nights. This is a kind of bed-and-breakfast scheme instigated by central government which, few years ago, offered 50 per cent repair grants to house owners if in turn they would offer accommodation to tourists.
The scheme has been enthusiastically taken up in the Minho and in this area alone there are 90 houses you can stay in. There are three different types of accommodation: the THs which are quite grand, the TRs which are smaller country houses and the ATs which are farms. Even in a TH you can get a room at less than half the price of a room in a typical pousada.
In the gentle, quiet country just north of Gandarela we stayed at the Solar de Souto, an 18th-century manor house set in a superb garden of topiary and old camellias. Margarida Almeida gave us the best dinner of our entire stay while her 18-year-old son practised his English on us.
Not all places provide dinner and not all suggest you eat meals with the family. At Casa de Sezim, south-west of Guimaraes, Antonio and Maria Pinto de Mesquito do things differently. The house, which has its own vineyard, is set round three sides of a courtyard, the fourth filled by a monumental entrance. They have turned all the rooms on the right-hand side of the courtyard into tourist accommodation, with a separate dining-room on the ground floor. Breakfast is brought over from the family kitchen.
The area round Guimaraes is now one of the most densely populated parts of Portugal but Casa de Sezim has wide elbows. We slept in a big carved 17th-century bed from Goa, and opened the shutters in the morning on to a wide verandah scattered with cane armchairs. Beyond was a fountain and a parterre of clipped box. Here you can indulge in folie de grandeur to your heart's content.
For details about the pousada and the Turismo de Habitacao schemes contact Portugese National Tourist Office, 22 Sackville Street, London W1 (071-494 1441). Turismo de Habitacao prices start at around pounds 40 for a two-bed apartment. Pousada prices range from pounds 30-pounds 80 for a double room.