JK Rowling and the £250,000 magical land – in her garden

She has fired the imagination of millions of young readers across the world with her tales of the boy wizard Harry Potter and his fantastical battles against the evil Lord Voldemort.

So when it comes to building a treehouse for her children, JK Rowling was always going to go further than a couple of planks nailed to the branches. The multi-millionaire author has submitted a £250,000 plan for two luxury arboreal residences in the back garden of her Edinburgh mansion.

Described as looking like something from one of her own adventure stories, the two-storey dwellings feature secret underground tunnels. trap doors, a spiral staircase, a fireman's pole to slide down and will be linked with a rope bridge.

At 12m (39ft) high, the tree houses are so big the writer needs to get approval from Edinburgh City Council before builders can start work. Drawings submitted to planners show one of the houses features a perch for what appears to be an owl and a "nature box" built into the cedar shingle covered roof for birds to nest.

Last year Ms Rowling was given permission to demolish a £1m 1970s house next door to her 17th century, 33-room mansion to make her own garden larger. She was also given approval for a summer house that critics said looked like the stone hut inhabited by Hagrid, the giant groundsman from her best-selling novels. At the time, a public meeting discussed her plans, but did not attempt to halt the hut being built.

Residents that share the same cul de sac in the exclusive suburb of Edinburgh have watched as her garden has been dug up and re-modelled in a renaissance style. Giant trees have been lifted by a crane over the walls to give the author and her family more privacy. Ms Rowling, 46, lives there with her husband Dr Neil Murray, and three children.

A spokeswoman for Edinburgh City Council said: "If there are more than six objections it will go to the planning committee." A spokeswoman for Ms Rowling said she would not comment on a private matter.