IT is, quite simply, a book lover's heaven.

Barter Books is one of the country's biggest second hand bookshops - approximately 300,000 books, meticulously arranged, easy to find and not a sniff of mustiness.

New Statseman magazine called it "The British Library of Second Hand Bookshops" and Bishop Auckland novelist Wendy Robertson described it happily as "a sweetie shop for book-a-holics".

Train-lovers might like it too. For the bonus is the shop's premises - set in Alnwick's magnificent former railway station, built in 1887 on a tremendously grand scale so that royal visitors to Alnwick Castle wouldn't feel they were slumming it.

The station, closed since 1968, is full of life again. A coal fire's still burning in the old waiting room and today visitors to the shop can sit there with a cup of coffee and browse through some of those books and listen for the ghosts of old steam trains.

The shop opened 12 years ago when County Durham lad Stuart Manley was using the station as a small toy factory. His American wife Mary decided to open a secondhand bookshop based on the barter system and started out in a small corner of his premises. Now the books have taken over, but it is still - perhaps because Stuart loves railways - recognisably a station and there is evidence of a great deal of loving restoration work.

The shop entrance is the old parcels' room, with the window where passengers once bought tickets. The old station entrance is now the children's room - complete with low shelves, bean bags and toys.

The ladies' first class waiting room is now the oversize books room and the gents' first class waiting room houses rare books on history and topography.

And what was once the platform is now the huge main book room. A display tells you all about The Aln Valley Railway Project - another of Stuart's dreams - which aims to restore the three mile link to the main line at Alnmouth.

As you wait to pay or browse part of the local history section, a small train circles on a track above your head. And when you look up you see the Manleys' other pride and joy - the Famous Writers mural - a huge painting by local artist Peter Dodd featuring almost 40 life-size writers. Jane Austen, Dorothy Parker, Alan Bennett, Oscar Wilde, Angela Carter and Wilfred Owen, among others, all seem to be leaning over the balcony looking quizzically down on us.

Which authors to choose for the painting was a nightmare for Mary Manley. Writers not only had to be her favourites but also recognisable. Tricky. But the result is a gem.

But head down for the books.

Sections range from antiquarian and, antiques, archaeology and architecture, to war novels, Westerns and women's studies and just about everything in between.

My quickly and randomly chosen favourites were the 1901 Telephone Directory - a volume about the size of a modest theatre programme and covering the entire British Isles, when the only people in the region who had phones then were apparently the Duke of Northumberland and one of his equally aristocratic friends - and the 1967 Bunty Annual, when the Four Marys were in their prime.

Nostalgia, says manager Gordon Castle, is usually more of a boys' thing - grown men snapping up old Dandy and Beano annuals, and the Eagle.

Biggest sellers are probably romances - shelves and shelves full of them, "and anything to do with Tolkien, Harry Potter or Jane Austen".

Slowest sellers are theology, apart maybe from CS Lewis. Those old thrillers from the 1940s and 1950s aren't too popular these days either. But turnover is high and stock is constantly changing. Many customers are regulars. Customers are divided just about equally between cash and barter customers - bring books back and you get a timeless credit note against future purchases.

The shop is a great place for tourists - they've just got their coveted brown sign . "It's somewhere to go on a rainy day, get a coffee, sit by the fire," says Gordon. "And let's face it, we do get a few rainy days up here."

Locals love the shop and regular customers come from a wide area, from the Scottish Borders down to Middlesbrough.

One of the many things that makes the shop special is the sheer breadth of its range. As well as all those romances, detective stories, and science fiction selling cheap and cheerfully, around the main room are 50 display cases featuring antiquarian books (and where I spotted the telephone directory) - all assessed by a professional valuer and costing serious money.

Staff are friendly, cheerful and helpful and have ranged in age from 16 to 76, from all sorts of backgrounds. And many of the customers are noticeably not typical bookshop customers either, but it's great to see children especially so enthusiastic about what's on offer. This is definitely a place where books are meant to be picked up, looked at and read.

As well as the books, there are CDs, videos, LPs, cassettes and sheet music. There are computers and coffee.

If you're making a trip to Alnwick to take in the Duchess' splendid new gardens as well as the bookshop, here's a tip - go to the gardens first. Because once you get into Barter Books, you might not get out in a hurry.

* Barter Books, Alnwick Station. Tel: (01665) 604888. Summer opening hours 9am to 7pm every day. Free parking. Good disabled access.

No cafe, but coffee and biscuits available.

Brilliant web site and web catalogue.

If you're bringing more than one bag full of books to sell, please contact them first.