I looked into the eyes of God, and they seemed kind and alert. I raised my hand to his cheek, but was warned not to touch. After all, he was 800 years old and his skin was flaking off.

The Portico of Glory, right, of Santiago de Compostela's cathedral in northwest Spain, hailed by Jan Morris as "unquestionably one of the great buildings of the world", has been admired by pilgrims to the supposed shrine of Saint James since the 12th century.

But apart from the stonemasons of the time (and a 17th-century artist who touched up the colour) few have seen the magnificent portrayal of Judgment Day as close up as I did last week. After more than eight centuries, this jewel of European Romanesque architecture is being restored.

The process will take up to two years during which visitors – in groups of ten, eight groups a day – are (services permitting) led up clanking scaffolding to admire face to face the happy throng of evangelists, prophets and angels swathed in intricately folded tunics, writing manuscripts or chatting, it seems, amongst themselves. Arching over everything are 24 celestial musicians playing lutes, zithers, harps and a two-handed hurdy gurdy, their feet tucked up in all positions. The Barrié de la Maza cultural foundation, which is funding the €3m restoration, copied the instruments in wood and found they produced the sweet sounds of medieval troubadours.

The restorer, Concha Cirujano, examines every curvaceous millimetre in her hard hat to assess the damage wrought by time, daylight and north-west Spain's fierce Atlantic winds and rain. "The main problem is that the non-porous coloured surface has worn away from the porous granite beneath, which absorbs moisture and causes deterioration," she tells me.

"We don't aim to restore it as it was, but halt further damage: to conserve, not to reconstruct." So they won't replace the once vivid blues, reds and gold, and Panstick-like flesh tones, but stabilise the masterpiece to survive further centuries of weather and shifting light filtered through the baroque outer façade.

A model city

My friend, Cristina, said: "Meet me in Alameda Park, by the Two Marias." Searching fruitlessly for a pair of granite virgins, I asked an elderly local for guidance.

He pointed to two figures of heavily made-up, brightly clad, beaky old spinsters. "I knew them," he said. "They were sisters, a bit ..." he touched his temple, "who paraded here every lunchtime, and the students teased them." He added: "They'd suffered in the Civil War, and the Socialist mayor helped the family, and commissioned these figures in their memory." Ancient or modern, Santiago's statuary is refreshingly down to earth.