BROCKEN MOUNTAIN, Germany, May 1 (Reuters) - Pity Saint Walpurga, the English nun from Devon. A night of 'devil worship' atop a German mountain is not how she would have wanted to be remembered.

When canonizing Walpurga on May 1, 870 for converting pagan Germans, Pope Adrian II hoped to Christianize a much-loved heathen spring festival. The plan failed, but Walpurga's name stuck.

Today 'Walpurgisnacht', or May Eve (the night of April 30-May 1), is an occasion for revelry and excess in much of northern Europe, but no more so than in Germany's Harz mountains, a remote region of dark pine forests, eerie rock formations and blustery peaks.

The beautiful villages of timber-framed houses and cobble streets snaking around the base of the Brocken and nestled in the valleys of the Harz are a huge tourist draw, each laying on bonfires, music and spectacle to mark Walpurgisnacht.

In the little village of Stiege, Satan is rowed across the lake in a flaming torch-lit boat after nightfall to lead dancing around the bonfire.

Elsewhere, with the help of cables, witches appear to fly overhead while in Thale, men from aroundnorthern Europe and Scandinavia compete in a terrifying speed chainsawing competition, carving diabolical creatures from logs of wood.

Down in the valleys, as devils dance with their plastic horns flashing, one hand holding a trident, the other a beer, Walpurga is toasted.

"I love dressing up, and I love all the myths and history attached to Walpurgisnacht," said Waltraud Scheller, 63, from Hamburg, supporting a giant plastic raven on a staff.

"And of course I know all about 'Faust' and Walpurga."

The reference is to Johann Wolfgang von Goethe, Germany's most famous writer. He climbed the Brocken in the dead of winter in 1777 and returned twice, writing a scene about Walpurgisnacht and the witches' celebrations in his masterpiece "Faust" - the tragedy of a man who sells his soul to the devil.

That helped imprint Walpurgisnacht further onto the German psyche and instilled the legend with new potency.

"The Harz mountains were a 'terra incognita', they were barely inhabited," said Jochen Klauss, a Goethe expert at the Klassik Stiftung Weimar. "It was one of those corners which were only discovered as a destination during the 19th century and at the start of the Romantic period, when people wanted to discover nature and experience the uncanny."

FOG-SHROUDED PEAK

The Harz mountains were one of the last places in what later became Germany to convert to Christianity.Brocken Mountain, the highest peak which is shrouded in fog 300 days a year, provides a natural stage for the supernatural and fantasies about evil.

The fog creates an optical illusion of magnifying the observers' shadow - a phenomenon known as the Brocken spectre.

A legend arose of witches mounting their broomsticks on the eve of May 1 and flying up the Brocken to commune with the devil. The fantasy inspired stories and drawings, each more grotesque and outlandish than the last.

Goethe took to the mountain to get over his sister's death, to question whether his life was on the right path, and to escape the constraints of Weimar society. It reinvigorated him.

Today a rock opera version of his "Faust" is staged every year in a hotel on the summit of the Brocken and a vintage steam locomotive hauls an audience dressed as devils or witches up the narrow gauge railway line opened in 1898.

For almost 30 years, however, during the time of Germany's Cold War separation, the Brocken, which lay on the border between West and East, was closed.

"Back in East German times there were no publicly organised Walpurgisnacht celebrations here and nobody dressed up. The mountain was closed," said Thomas Hahne, 53, who works in the kiosk on the summit of the Brocken and grew up nearby.

Like Pope Adrian, East Germany's communist authorities frowned on Walpurgisnacht's pagan associations and tried to focus on workers and trade unions on international Labour Day.

"We had 'dance into the May' events the night before instead," Hahne said, adding that he finds today's revelries too commercial and lacking in spirituality.

"There are no druids, no religious aspects, this is just people dressing up," he said.