STEPHEN LEWIS is delighted by a new guide to York's green places.

YORK is a green city. Not because we are more environmentally friendly than people elsewhere (although it would be nice to think we do our bit). But because the city itself is green.

Over the centuries, York's growing built-up areas have surrounded and enveloped ancient strays and commons, woods and riverside meadows. Some of these have gradually been tamed, to form public parks and gardens. Others, however, have remained virtually unchanged down the years remnants of old countryside woven into the built-up fabric of the city.

We all have our favourite public park or local stray: Rowntree Park, say, or Micklegate Stray or Fulford Ings.

But hidden in the heart of the city there are also a host of less well-known green places, tiny little oases of nature in the heart of a bustling modern city.

Many link to form green corridors along the city's two main rivers, or running beside old footpaths or half forgotten lanes.

Others are individual little gems unknown to all but those who live nearby.

Now Sessions of York has teamed up with the York Natural Environment Trust and City of York Council to produce a wonderful new guide to more than 40 of the city's green spaces.

They range from popular favourites such as St Nicholas Fields and Monk Stray to riverside promenades, Edwardian parks, ancient meadows, woods and wetlands.

We all know about Hob Moor. But how many of you have heard of Bachelor Hill a little, grassy hill off Askham Lane topped with a copse of pine trees that offers unparalleled views across the city? Or Heworth Holme six acres of wet grassland running alongside Tang Hall Beck with a small wood on the higher ground?

Mick Phythian, chairman of the York Natural Environment Trust and one of the contributors to the book, says the aim was to open up many of these lesser-known green spaces so people would know about and use them.

"People just don't know that these sites exist and that there are so many of them," he said. "They are wonderful places, and they have all got their own different qualities. We want to get people out and enjoying them."

The book was the idea of Bill Sessions, of Sessions of York, Mick said. "Although he lived quite close to Clifton Backies, he never knew how to get there."

The new book, complete with detailed, lovingly hand-drawn maps by Judith Ward and some wonderful photographs, many by Lisa Pickering of www.yorkstories.com, gives you all the information you need to explore these secret places.

Between them, they add up to one of the most beautiful features of an already beautiful city, says Dave Meigh, City of York Council's head of parks and open spaces and another contributor to the book.

"There are the strays and the river banks, but also lots of green nooks and crannies," he says. "You can get lost' in them, get right away from the stresses and strains of modern life even though you're right in the middle of the city."

So, who needs that foreign holiday? There are more than 40 wild places right here in York for you to spend the summer exploring. Enjoy.

York's Green Places, compiled by Judith Ward and edited by Dave Meigh, Mick Phythian, Bill Sessions and Elizabeth Smith, is published by the Sessions Book Trust, priced £5. It is available from local bookshops, or direct from Sessions of York (add £1.50 for postage and packing), Huntington Road, York YO31 9HS.

Some of York's hidden green places...

Clifton Backies: one of Mick Phythian's favourites. Ancient ridge and furrow meadowland between Burton Green and Water Lane that was partly used as an airfield in the Second World War. Completely open access, with a range of habitats including "unimproved" pastureland of wild flowers and grasses, scrub woodland, pond and wetland and old hay meadow. Lots of different bird species.

Bachelor Hill: another of Mick's favourites. Grassy slopes, a hilltop copse of pine and horse chestnut trees, an old sand pit and fine views across York to the Yorkshire Wolds and North York Moors (who says York doesn't have any hills?) make it a great place for a picnic. The rough grassland around the sand dune is home to lots of different butterflies.

Acomb Wood: one of Dave Meigh's favourites. Ten acres of mixed woodland and ancient pasture right in the middle of a large housing estate in Foxwood. Divided into two halves by Acomb Wood Drive, it includes magnificent 250-year-old oak trees, uncommon woodland wild flowers, and surrounding hedgerows. Lots of birds and small mammals. Dave is particularly fond of it, he says, because there is so little woodland in the Vale of York. Yet we have one here right in the heart of the city.

Moorlands Nature Reserve: Eighteen acres of mixed woodland, developed in the 20th century as a woodland garden, that is just north of the ring road. More than 50 species of birds, a host of wild flowers from snowdrops and daffodils to bluebells and rhododendrons. A special rhododendron walk through a series of glades, a heath, ponds, and a glade of ornamental maples under mature oak trees.