A millionaire landowner has defied the recession by having an extravagant 65ft folly built on his estate.

The lavish structure is thought to be the tallest folly to be built in Britain in over 100 years.

Owner William Gronow-Davis has spent tens of thousands of pounds on the structure which sits in the grounds of his 7,500 acre Rushmore Estate in Dorset.

By the very definition of a folly, the building is useless and serves no purpose.

But to Mr Gronow-Davis it “finishes off” his garden and adds to the spectacular vista from the drawing room of his mansion home one mile away.

Bournemouth Echo: The folly in all its glory Pictures: Phil Yeomans, Bournemouth News

Although the gardens of Rushmore are a designated Area of Outstanding Natural Beauty of parts of it are Grade II listed, the hulking structure was given planning permission.

The folly was to originally incorporate five mobile phone masts and was to be funded by O2.

Planners viewed the need for the new aerials outweighed any conservation worries.

But the mobile phone giant pulled out of the deal and Mr Gronow-Davis decided to go ahead with the proposed folly.

The design of the folly is in an Indian Mogul style to reflect the fact Mr Gronow-Davis was born on the sub-continent.

It has five copper domes on the roof that are capable of housing the phone aerials in the future.

Mr Gronow-Davis, a descendent of General Augustus Pitt Rivers, who inherited the estate in the 19th century, said: “It is unusual and looks so beautiful from my house.

“From my drawing room you look out onto the gardens along an avenue of trees and fountains and about a mile away is the folly.

“It is wonderful and just finishes the garden off.”

He added: “I would say that 99 per cent of the feedback I have had has been positive. Natural England has said it enhances the landscape.”