BETWEEN THE WOODS AND THE WATER by Patrick Leigh Fermor (Elisabeth Sifton Books/Viking $18.95. 248 pp.)

In 1933, Patrick Leigh Fermor set off on foot from the Hook of Holland with the object of walking to Istanbul or, as he preferred to think of it, Constantinople. It was a romance as much as a journey, and it began the career of a man who may be the finest living travel writer in the English language.

“Travel writer” is almost a misnomer. Fermor, author of “Mani” and “Roumeli”--books about Southern and Northern Greece, respectively--and of “The Travelers Tree,” set in the Caribbean, travels as if there were no maps. Nobody has ever been where he goes; not because he ignores history or other travelers’ writings--he reads them assiduously--but because his eye makes new what it sees.

The 18-year-old’s adventure, which took a year-and-a-half--what with frequent stopovers and falling in love--is now being told by the septuagenarian writer. “A Time of Gifts,” which came out two years ago, got young Patrick as far as the Danube. “Between the Woods and the Water” takes him through Hungary and Transylvania, ending up at the Iron Gates on the Danube once more.

Nowadays, he would call it Eastern Europe. Before World War II, it was thought of as Central Europe. The Austro-Hungarian Empire had only been gone for 15 years, and if Patrick spent nights with Romanian-speaking shepherds whom he fancied as lineal descendants of Vlachs and Dacians, he spent others with barons and counts who wore tweeds, spoke English and French as well as they did Hungarian or Romanian, and belonged culturally and historically to the old Mittel Europa.

Eastern Europe proper--Bulgaria, Eastern Wallachia, Bessarabia--still lies ahead when this volume ends. Patrick, at the Iron Gates, is reciting names to himself: Stephen the Great, Michael the Brave, Mircea the Old, Vlad the Impaler, Basil the Wolf, John the Cruel, Ear-Ring Peter, Radu the Handsome. And imagining:

“Plains with dust-devils twirling half a mile high, forests and canyons and painted abbeys; swamps populated by strange sectaries, limitless flocks and drovers and shepherds with peculiarly shaped musical instruments; and, scattered among the woods and the corn fields, manor houses harboring overcivilized boyars up to their ears in Proust and Mallarme.”

What is happening here? Using half-legible 50-year-old notes and examining his own memories, Fermor goes back to the middle 1930s to evoke an avid 18-year-old who is dreaming what he will see and think six months later. This captivating book is as much a journey in time as in space; as much an old man’s encounter with his young self as it is an account of sights and people.

At 18, Patrick is dazzled with his adventure: “My attitude towards life resembled a sea-lion’s to the flying bloater.” He is drunk with the exotic. He revels in strange place names, and the sights and sounds of what he once read about, and now is walking through. Like Don Quixote, he is on a literary high that has become reality.

One of his Budapest hosts lends him a horse from her country estate to ride across the Hungarian plain. She and her children drive him out to meet the horse, and then drive back to town. But he thinks of the parting in full colors: “They for Pest, I for Constantinople.”

Mounted, he stops at a peasant’s cottage and accepts a glass of milk from an old woman. “I’m drinking this milk on a chestnut horse on the Great Hungarian Plain,” he thinks. In his mind’s eye, he is a young Rupert of Hentzau. Next stop, Zenda.

Partly in his mind’s eye, that is. And partly in the mind’s eye of the 70-year-old, refracting the young romantic with a slight tilt of his prism that is neither ironic nor sentimental but simply registers that time has passed. It is like the hand you shade your eyes with to get a better view of the sunlight.

“In youth is pleasure,” the song goes. Everything exhilarates oldPatrick’s-young-Patrick-enough, now; I’ll call him Patrick. His first night in Hungary, he goes to an Easter procession whose pageantry puts him in full tongue. The local archbishop gets into his carriage, and Fermor writes:

“His gentleman-at-arms, helped by a chaplain with a prominent Adam’s apple and pince-nez and a postillion in Hussar’s uniform, were gathering in his train, yard upon yard, like fishermen with a net, until it filled the carriage with geranium-colored watered-silk.”

Introduced by a letter from friends in Germany, Patrick was the mayor’s guest. It was a chain-letter, in fact. Throughout Hungary and Western Romania, he is passed from squire to baron. One night he shares hard-boiled eggs with two swineherds; the next, he is playing bicycle polo with a count and his household.

Sometimes he feels he is straying from his intention to live like a pilgrim. But after all, he tells himself, the wandering scholars of Provence used to hang around the chateaux. “Raven-fed like Elijah,” he writes, “I was no longer surprised but I never stopped rejoicing.”

The portion of his journey encompassed by this volume may lack discipline or, for that matter, distance; but it makes up for it in richness of texture. His account of the rural Hungarian gentry is a portrait of a world that was fading and would perish in World War II.

Meanwhile, it flaunted its colors and its appealing eccentricities. One host kept a shotgun by the piano while he played Bach fugues. Every few minutes, he broke off to rush to the window and fire a shot into the air. In a few seconds, Fermor writes, “Like a heavy parcel, down on the lawn crashed a bird from the enormous rookery that overlooked the house.”

Another count collected moths and researched the provenance of the Ashkenazic Jews. His English was perfect except that, thanks to a Highland nanny, it was Scottish. “Sit ye doon,” he welcomes Patrick. Later, ruminating over a tricky decision, he remarks: “I’ll dree my own weird.”

Patrick spends weeks in these retreats. And he spends months rambling around the countryside with Istvan, who becomes his best friend; and Angelica, with whom he falls playfully and then seriously in love. It is a golden time and--here the septuagenarian perspective--a doomed one. Few of these friends survived World War II?.

Patrick’s adventures and encounters are interwoven with historical reflections on all manner of things, ranging from the quarrel between the Romanian Unate and Orthodox Churches, the rise and fall of the Avars, Pechenegs, Magyars, Gepids, Turks, Jazyges and other dominations that fought each other over the centuries. He will pause to wonder if the elephant sent by Harun al Rashid to Charlemagne stopped for a drink at the particular stretch of the Tisa River he is tramping along.

Sometimes the young Patrick’s scholarship dawdles, helped, as older Patrick admits, by his own trips to the library. No matter. It is like walking with a puppy. He wanders off to dig at some hidden obscurity, but we don’t mind the wait. It is a wonderful morning he is taking us through.