One of the last unspoilt quarters of traditional Beijing is facing demolition under a £500m "restoration" plan.

Conservationists argue that the plans will irrevocably damage one of the Chinese capital's social and architectural jewels.

The 30-acre development around the ancient Drum and Bell Towers, which were used to tell the time in the Yuan, Ming and Qing dynasties, will see traditional crooked courtyard houses and winding alleyways replaced with a themed 'Beijing Time Cultural City".

Over the last 20 years mile after mile of Beijing's "hutongs", or alleyways, have been bulldozed to make way for gleaming skyscrapers and apartment complexes as the city engages in a whole-scale, and at times brutal, program of modernisation.

The plan is allied to an ambitious 20-year project to create an "underground city" by digging out three square miles of northeastern Beijing to create a network of shopping malls, car parks and even a three mile underground road.

The area around the Drum and Bell Towers has been a vibrant part of Beijing since the days of the Ming Dynasty (1368-1644) and in recent years has reinvented itself as a faintly bohemian cultural quarter with chic boutique shops, small galleries, restaurants and courtyard hotels.