The crucial event was the capture of a trainload of troop reinforcements and ammunition. Guevara's men fought their way to the railway line and ripped up the track, derailing the train, seizing the spoils and smashing Batista's plan to halt the rebel advance on Havana. At the spot, now a calm suburban level crossing, stands a museum dedicated to the event. Beside the track - Cuba's west-east mainline - a zigzag of brown goods wagons artfully resembles a derailment. Steps lead to open sliding doors and inside is the story of the Battle of Santa Clara.

Around the world, Guevera's name went out on the wire services - in full: Dr Ernesto 'Che' Guevara - and he's never looked back. His dying in Bolivia in 1967 in a futile guerilla campaign only sent the legend into overdrive; he became a worldwide youth hero and poster pin-up, and nowhere more so than in Cuba. There he is El Che, the great exemplar of revolutionary courage and determination, the official No 1 hero. And Santa Clara is his city, officially dubbed La Ciudad del Che.

Despite being an Argentine and a qualified doctor, Guevara gave his life to the Cuban revolution. Santa Clara is where the Cuban regime chose to commemorate him. The city is roughly in the centre of this long crocodile of a country and it makes a good national meeting point - Pope John Paul II gave a multitudinous mass here in 1998. But not, for obvious ideological reasons, in the place actually made for great gatherings: the Plaza de la Revolucion.

This enormous concrete spread is overlooked by an immensely long stone platform topped with great stone slabs and blocks carved with reliefs and inscriptions, notably Guevara's emotional farewell letter to Castro on leaving Cuba in 1965. On the tallest block stands the big Guevara statue, seven metres of black bronze. Deep under the platform, as if to suggest the secrecy of their struggle, a museum commemorates the core revolutionary band of the Sierra Maestra, telling their valiant story with photographs, documents and artefacts.

A special section is dedicated to Guevara's life. It has everything from his third-grade school report to his asthma inhaler plus an original print of that image seen worldwide on T-shirts, posters, trucks, walls and coffee mugs. Alberto Korda's 1960 grab-shot at a Havana memorial event is reckoned to be the most reproduced photograph. In a dimly lit grotto by an eternal flame lie his remains, finally recovered from Bolivia in 1997.

What the museum doesn't cover, however, is the ruthlessness and blundering that accompanied his vaulting bravery. But never mind the reality, feel the myth - that's what Santa Clara is about.

After all this celebration of struggle, it's odd to discover Santa Clara was founded as a safe haven from violence. The great prize of the colonial Caribbean, Cuba was prey to marauding pirates who regularly attacked its rich port cities. The buccaneers even struck inland if the pickings were worth it, as they were at Remedios, today a beautiful colonial town that reflects its former eminence.

In 1689, some fed-up citizens left vulnerable Remedios and founded Santa Clara 40km farther inland, amid good, flat farming land. In 1867 it became the provincial capital and in 1873 the railway reached it from Havana, boosting its prosperity and importance. In a skirmish of the 1890s independence war, the Spanish army shot rebel Colonel Leoncio Vidal from his horse in the central square; now it's named after him.

Parque Vidal has a lush palm-tree-shaded garden at its centre with an enormously wide concrete promenade encircling it. The width comes from a feature of the old slavery days: there were separate paths, one for strollers of European descent and one for those of African descent.

Despite the general quaintness, dominating the square is one of those 1950s buildings that are often the most modern you can find in Cuban cities, which generally appear to have missed out on the past half-century. The Hotel Santa Clara Libre is 10 storeys of pastel green modernist concrete confusingly labelled 'Cine Camilo Cienfuegos'; the city's leading cinema occupies the hotel's depths.

Camilo Cienfuegos was one of Guevara's fellow commandants, leader of another column that helped take Santa Clara, but his young life ended in a plane crash less than a year later. In Cuba, Cienfuegos is second only to Guevara as a revolutionary hero and martyr.

In one of those characteristically Cuban revolutionary commemorations-cum-propaganda coups, in 2004 the cinema hosted the Cuban premiere of The Motorcycle Diaries, enthusiastically attended by Gael Garcia Bernal, who played the young Guevara in the road movie.

The state-run block began life as the Gran Hotel Santa Clara Hilton in 1954. Nationalised soon after the revolution, like all Cuba's hotels, it remains the tallest building in town, which gives an idea of just how little Santa Clara has changed in half a century. From the top storey flaps a big black and white picture of Guevara on what appears to be a king-sized bed-sheet; as so often throughout the world, it is a version of the classic Korda image.