Northern Spain; Following the pilgrim route to Santiago de Compostela

Northern Spain is not the Spain the traveler has come to expect. Its Atlantic coast is as green and rainy as Ireland's, its rushing rivers are full of trout and salmon, and in the fall its stone mountains blaze with unexpected red and gold foliage.

Northern Spain's history is different, too. In the Middle Ages - while the Moors were still decorating southern Spain with palaces and mosques - the north, already free of Moorish domination, was building Romanesque churches and monasteries along the pilgrim route of St. James that led to Santiago de Compostela on Spain's northwest coast.

According to one legend, the apostle James, was buried finally at Compostela; Iago is Old Spanish for James, hence the name. Legend later made St. James the great defender of Christianity against the Moors. By the 11th and 12th centuries , half a million pilgrims gathered each year in Paris along the Rue St. Jacques (James) to walk the way of St. James, which was next in importance to the Jerusalem and Rome pilgrimages. We know the details, because in 1130 a French priest, Aymery de Picaud, wrote what might be called the first travel guide describing the splendor and hardship of this pilgrimage.

On an October trip we followed a portion of this route; the pilgrimage church of Santiago was one of our goals. We detoured from the way of St. James twice, crossing the Cantabrian Mountains to Santillana and the Altamira caves, and after Compostela following the ria-slashed coast of Galicia to Bayona for two days of relaxation before crossing into Portugal.

This 700-mile journey took five days and included luxurious lodging at two paradores and two hotels of the National Tourist Corporation of Spain, all converted from historic buildings.

We ate splendidly, too. Actually the food in paradores and hotels can be dull; we found it more interesting to skip the international menu of several courses and ask for the specialties of each region. In this way we enjoyed the superb trout and salmon of mountain streams and the shrimp, scallops, oysters, and eels of the Atlantic.

We entered the pilgrim route at Burgos, directly north of Madrid. This city's ugly industrial suburbs offer a poor introduction, but the gray Gothic core of the old city recalls its past as the ''Cradle of Castile.'' Narrow houses with glass balconies look down on little plazas with off-center fountains. The old city is entered by the Arco de Santa Maria. A portrait-figure of El Cid, the Moor fighter, is carved here. It is dumpy and bearded, scarcely Corneille's hero , but perhaps more like the crafty fellow he was. Born near Burgos, he is buried in its cathedral.

It took 300 years to build this great Gothic church, whose dark stone is richly carved and piled with fretted turrets and open-ribbed spires. The interior is somber, blocked as in many Spanish cathedrals by the square bleak coro (choir). The gloom was intensified by a steady rain.

Crossing the Cantabrian Mountains, the rain turned into fog and light snow. These difficulties doubled our enchantment with the lush, green world on the other side - the valleys and round hills, bordered with stone walls and hedgerows.

This rural verdure is the setting for tiny medieval Santillana. Its four cobbled streets are lined with ancient stone houses emblazoned with heraldic shields. Since 1889 Santillana has been designated a national museum, albeit a museum in which the inhabitants lead a lively daily life. The men go about their work in cow-country boots; the women wear curious wooden clogs. The stone palaces are homes, softened by pots of geraniums and wooden balconies, often hung with washing. Many of the lower floors are cow barns. Others house artisans , some of whom make the most beautiful furniture in Spain.

Parador Gil Blas takes its name from the hero of Lesage's picaresque novel. Staying in this old palace of the Barreda family made us feel as if we, too, were part of the medieval idyll. To reach our room we walked past antique chests , tapestries, and armor; an enormous iron key opened our door. When we pushed back the red velvet curtains and wooden shutters, we looked down on the parador garden and tile roofs. The sounds that floated in were those of cow bells and wooden wheels on cobbles. Only our enormous white-tiled bathroom brought us back to the 20th century.

We remained here in baronial splendor for two nights. We wanted to savor the town and its fine Romanesque church and cloisters of Ste. Juliana. We also wanted to see the Altamira caves, just a mile and a half from the town.

To protect these cave paintings the Spanish government allows only 20 people to enter at one time. This was no problem in the fall. However, it is well worth any amount of waiting.

The main picture gallery is 50 feet long; the entire ceiling is covered with bison and an occasional horse or deer. The primitive artists used the irregular surface in a very sophisticated way to emphasize body contours. Outlined in black, painted ocher and blood red, the colors are as fresh as if painted yesterday instead of thousands of years ago.

Scholars have speculated about the meaning of the paintings; it seems significant that there are no hunters or weapons. Whatever the purpose, the impact is staggering.

On our third morning we drove along the seacoast, past lush meadows indented by rivers and inlets. Returning inland, we climbed into mountains splashed crimson beneath variegated rock peaks.

Leon, like Burgos, has an old walled town within its modern city. Here all is built of honey-colored stone. The Gothic cathedral is Spain's simplest and perhaps most beautiful. It is enhanced by carving, but its glory is the immense expanse of stained glass that lights the interior with flamelike warmth.

Romanesque San Isidoro is equally impressive. It is most famous for its 12 th-century frescoes in the Royal Pantheon, burial vault of the kings of Leon. The shallow domes are painted in white, terra cotta, and blue, touched with gold , for an effect of jewel-like brilliance.

We stayed in Leon, as the pilgrims did, at the Hospice and Monastery of San Marco, now converted to a luxury hotel. Scallop shells, the symbol of St. James, are carved on its handsome Renaissance facade. A functioning chapel has been retained in the left wing and, separated from the hotel only by a sheet of plate glass, the museum of San Marco houses a collection of church ornaments. Among them is a small 11th-century ivory Christ, one of the most moving sculptures I saw in Spain.

We dined overlooking the garden, and slept under brocaded baldachins. I thought of the pilgrims who probably slept here on straw pallets.

The next morning we stopped in Astorga to gawk at the black and white fairy-tale castle next to Astorga's rose-red cathedral. The castle, built by the 19th-century fantasist, Gaudi, as a bishop's palace, now houses a museum of St. James's way. In Ponferrada we detoured to the Knights Templars' castle, and in Lugo we circled the thick Roman walls.

We were now in Celtic Galicia. Against rosy heather we saw circular hayricks and granaries set on stone mushrooms as in Cornwall. We were not surprised to meet a group of young men with a bagpipe.

Santiago de Compostela is still a small town. Almost immediately we found ourselves in the square before the main facade of the cathedral. Delineated by four splendid buildings in amber granite, Obradoira is one of the handsomest plazas in Spain. Next to the cathedral is the Hostal de los Reyes Catolicos. Established by Ferdinand and Isabella as a hospital for weary pilgrims, it is now another luxury hotel. The bedrooms open out on four charming courtyards called Matthew, Mark, Luke, and John.

The Church of Santiago has been built and rebuilt. The main, or western, facade is exuberantly baroque; the southern, more austerely Romanesque; the eastern, Renaissance. It is the only cathedral in Spain that can be viewed from four plazas.

St. James sits atop the tree of Jesse, carved from the central column of the main arch. Traditionally the pilgrim to Santiago placed thumb and four fingers among the twisted stone stems. The custom is still observed, the stone now worn smooth by generations of hands.

Seeing Santiago is exhilarating, but exhausting. Instead of trying to explore the 40 other churches in the city, we retreated to Los Reyes Catolicos, where we were waited on by attendants in livery and white gloves, service fit for its royal founders.

Our final drive in Spain took us down the Galician coast, with its magnificent chain of fjordlike rias. At Bayona on a high peninsula that juts into the sea, a castle surrounded by handsome walls has been turned into a parador with the one of the most beautiful settings in Spain.

From our bedroom window we looked down on blue bays spotted with silvery islands. In October the pool had been drained, but it was still warm enough to play tennis and to sun and dip into the Atlantic from a sandy cove just outside the walls, the perfect complement to the pleasures of sightseeing.

Practical details:

Parador Gil Blas of Santillana: from June to September, $54 for double with breakfast; off-season, $41.50 for double with breakfast.

Parador Conde Gondemar at Bayona: from June to September, $67.50 for double with breakfast; March to June and October, $47.50 with breakfast; winter, $40 with breakfast.

Hotel San Marco at Leon: from April to October, $40 single with breakfast, $ 65 double with breakfast; off-season, $35 single with breakfast, $56 double with breakfast.

Hostal de los Reyes Catolicos: from April to October, $37 for single with breakfast, $48 for double with breakfast; off-season, $30 for single with breakfast, $40.50 for double with breakfast.

Reservations for paradores can be made through Marketing Ahead, 515 Madison Avenue, New York, N.Y. 10022, (212) 759-5170. For hotel reservations, phone (212 ) 838-4370.