San Francisco Frontiers - Macron visits Notre-Dame to mark fire anniversary

The cathedral is due to regain its famous spire by the end of the year, an identical copy of the 96-metre spire added in the 19th century by architect Viollet-Le-Duc, made from an oak wood structure and lead covering.

Its 80-tonne wooden base, resting on stone arches 30 metres above the heart of the cathedral, is due to be completed on Saturday -- four years to the day since the fire that shocked the world.

Police cleared the area around the cathedral ahead of the visit by Macron and his wife Brigitte, amid calls for protests at the site over his unpopular pensions reform, which faces a crucial constitutional court decision later on Friday.

The cathedral is due to reopen by the end of 2024, though not in time for the Olympics in Paris that summer.

The fire prompted a global outpouring of support and solidarity, including 846 million euros ($935 million) in donations.

Authorities say progress is "well advanced" on cleaning some 42,000 square metres (450,000 square feet) of walls, decorations and vaults, while stone masons have been rebuilding the collapsed walls since November.

Cleaning has also begun on the great organ, which was undamaged but coated in lead dust. Its 8,000 pipes will be reassembled one by one.

Plans for an internal redesign are due to be approved this summer, aimed at creating "an educational and spiritual journey" for visitors, according to Archbishop of Paris Laurent Ulrich -- "not the equivalent of a museum."

A judicial investigation is ongoing to determine the causes of the fire, while a judge is also investigating subsequent lead pollution.

The government this week announced 220 million euros to restore and secure 87 cathedrals around France.

C.Williams--SFF