A 'woodhenge' in Rothersthorpe and a new stone circle in Crick are both under construction.

The woodhenge is being constructed by organic cooperative Permorganics. Dawn Houghton, who runs the group, follows several pagan traditions and said the idea for the circle of 13 sacred trees came from a Permorganics member called Ant.

She said: "We were thinking about it right from the beginning of Permorganics and it is my husband who has been out digging. It's looking pretty good now."

Tree circles or Oghams were devised by Celtic tribes in the British Isles around 500bc, and druid people used to 'talk' at great length to the trees to develop an understanding of tree-lore.

The other structure, which will be made of four massive stones, is an art project being sponsored by the East Midlands Arts Council which will eventually stand on Cracks Hill, Crick.

The foundations for the circle will be set on Thursday, March 20 – the day of spring equinox – when youngsters from primary schools in Crick and Yelvertoft will mark the positions for the stones as the sun sets.

It is hoped the completed circle will be finished within five years. Keith Liggins, chair of the Friends of Cracks Hill, said: "We are pleased that the marking of the stones is happening this spring equinox and hope the villagers of Crick and Yelvertoft will join us on Cracks Hill."

And Dewi Morris, senior ranger for Daventry District Council, says: "This marks an important stage in the process of creating the standing stones at Cracks Hill. It is going to be a real spectacle and we would like as many people as possible to join us."

And Ms Houghton added she was very much in favour of the art project.

She said: "It's a really nice idea and I am delighted there will be more circles around. We can even come and officiate it if they want us to. The more circles the merrier, they are going to have historical value in years to come."

Anyone who wants to attend the marking of the Crick circle can go along to Cracks Hill on Tuesday, March 20 at 1.30pm or 6.15pm.