SAN LORENZO DE ESCORIAL, Spain (AP) _ The sweeping esplanade and the giant granite cross thrusting up from the surrounding mountains dwarf the schoolgirls and conscripts on an outing at the Valley of the Fallen.

The visitors giggle, shout and strut. They appear oblivious to the presence in the crypt behind them of the bones of 40,000 people who died fighting on both sides in the Spanish Civil War, which ended 50 years ago on April 1, 1939.

Neither the monument - built by Republican prisoners-of-war defeated by the forces of Gen. Francisco Franco - nor the memory of the three-year war itself seem to weigh very heaviliy on the spirit of a modern Spain.

The government of Socialist Prime Minister Felipe Gonzalez has planned no public observance for April 1, the day a half-century ago that ushered in a 36-year Franco dictatorship that outlawed the Socialist and all other political parties.

Socialists, Communists, liberals, anarchists, Masons and free-thinkers all suffered in the harsh repression that followed Franco's victory, which marked the end of his July 1936 uprising against the forces of the Second Spanish Republic.

Many who fought on the side of the Republic perished from hunger and ill treatment while hacking away at the granite mountains to build the Valley of the Fallen, 30 miles northwest of Madrid.

''The Socialists try to distinguish themselves from the Francoists by not keeping alive the memory of the Civil War,'' British historian Paul Preston explained. ''There's nothing good to remember. It wasn't really the end, it was the beginning of very difficult times for many, many people.''

A member of the Friends of Former Spanish Refugees said the government had agreed to help with their project to have as many indigent, elderly exiles as possible return to visit Spain this year - as long as no mention was made of the end of the Civil War that drove them away in the first place.

Jordi Corral Morales, a 21-year-old corporal in the army's elite Brunete armored division, knows that Franco lies buried beneath a plain, marble slab in the basilica, but he says he could care less about the man whose crusade for a righteous, rightist Spain was falling apart by the time the young conscript was born.

The Valley of the Fallen - which Franco designed as his final resting place - has been administered since 1982 by the National Patrimony in hopes, according to some, that it will gradually lose its fascist connotations and slip into the vast collection of old castles and monuments that dot the Spanish landscape.

Historian Javier Tusell and Culture Minister Jorge Semprun are both concerned about Spaniards' reluctance to confront their past and their lack of historical memory.

On the eve of the 50th anniversary and 14 years after Franco's death, ''it is striking that our country, which has gone through a peaceful transition from dictatorship to democracy, has not, however, developed a shared historic conscience,'' Tusell wrote recently in a Madrid newspaper.

''It's not a banal issue,'' he continued, ''because the image that a group projects of itself on the past indicates its willingness to live in harmony in the present and the future.''

Pedro Alvarez remembers the day 50 years ago when he and a group of other 12-year-olds joined the crowds in downtown Madrid that hurried to put out the appropriate flags as the remaining Republican troops fled and Franco's victorious Nationalist forces approached the Spanish capital.

''We rushed into a barracks the 'Reds' had abandoned and stuffed our pockets with potatoes and carrots,'' he recalled. ''Hunger was everywhere in Madrid during the war, and we were happy it was over.''

''The war didn't really end in 1939, the hardships and conditions of war continued well into the late 1940s,'' said sociologist Amando de Miguel. ''People didn't marry very much, a great sense of depression set in, there was a terrible shortage of food, and then, the guerrilla warfare against Franco went on into the 1950s.''

Semprun, who wrote the screenplay for Alain Renais' 1964 film, ''La guerre est finie'' (The War is Over) as a Spanish exile in France, warned attendants at recent academic conference that Spain will be in trouble without a historical memory.

To fill the gap, many of the country's leading newspapers plan special supplements dealing with the end of the war and its relevance today.

And a surprising success of the current literary season has been a novel entitled ''Luna de Lobos'' (Wolves' Moon), by 31-year-old poet Julio Llanzamares, the sparse tale of three men in the anti-Franco guerrilla movement who try to get to France through the mountains of northern Spain.

The late Spanish historian Claudio Sanchez Albornoz, who exhorted his countrymen not to forget the Civil War, wrote that during the 1931-39 Second Republic, Spaniards tried to carry out religious, political and economic revolutions that their European neighbors had taken centuries to realize.

French historian Pierre Vilar says it will be possible to date the real end of the Spanish Civil War to the time when the three revolutions have been carried out.