I went to Margate last weekend and it was shut. Just when I was beginning to wonder if the four-minute warning had been sounded, I stumbled upon the Shell Grotto, a beacon on a dark December morning serving frothy cappuccinos to a Frank Sinatra soundtrack. Despite being tucked away in a quiet sidestreet, business was booming at Britain's only underground shell temple (a magical place, not half as cheesy as it sounds). But this is not surprising when you consider that it's pretty much the only tourist attraction in town which bothers to open between November and March.

'It's not just bad for visitors but for the local community when everything shuts for the winter,' said Sarah Vickery, who took over the grotto 18 months ago. 'If the attractions close, then so do the gift shops, cafes and hotels. The resort dies.'

Sarah knew she was taking a risk by opening on winter weekends but it has paid off. 'The quieter winter months give us the chance to try out new things. We've hosted art shows, music recitals and poetry reading. We've even got Santa in the grotto until Christmas. You have to find ways of attracting a different kind of visitor from the ones who come in summer.'

Against a backdrop of plummeting visitor numbers to seaside resorts, it seems a trifle odd that the response of many tourist attractions is to put up the shutters and hibernate for the winter. But it's a scenario repeated at attractions across the country. All but a handful of the National Trust's historic properties are 'put to bed' on 3 November and do not reopen until Easter. A spokeswoman says it's necessary to 'rest' the properties and allow conservation work. But would it really hurt to keep them open just at weekends?

A quick flick through the Good Britain Guide makes for depressing reading. I want to take my nephew for a day out in Essex. What about the Colne Valley Railway? Closed. Castle Hedingham? Closed. Clacton Pier? Closed. In desperation I turn to the entry for Gnome Magic in Dedham. Closed! Even the gnomes have packed up for the winter.

'It's a Catch-22 situation,' laments Henry Ashworth, who runs the excellent Beach Hut restaurant and bar at Watergate Bay, Newquay. 'If everything is closed, people don't come. If people don't come, everything closes.' Though the restaurant is heaving on winter weekends with surfers and walkers coming in for a warming hot chocolate or a bowl of fish soup, Henry admits winter opening is not a huge money-spinner, but he views it as a long-term investment. 'Too many people see tourism as a nice semi-retirement option: work hard for three months in the summer and then put your feet up for the rest of the year.'

This seasonal approach is shortsighted for many reasons, not least because it stops people considering tourism as a career option. 'There is no incentive to invest in training if staff are only going to be working for four months of the year, and you end up with poor service,' says Henry.

This year the English Tourism Council launched a 'blueprint for the regeneration of England's seaside resorts'. It talks of the need to find a 'distinctive brand', of 'unity and vision' and a 'masterplan for action'. But surely a good starting point would be to take down the shutters and open for business?