The Great Globe was restored last year as part of the project
Work has started on a £5.5m project to transform a Grade II-listed castle at a Dorset nature reserve.
Durlston Castle, near Swanage, is being renovated and turned into a visitor centre for the Jurassic coast world heritage site.
It will form the centrepiece of the 280-acre Durlston Country Park and will house a shop and catering facilities.
A turf cutting ceremony took place earlier. The work is expected to be fully completed by July 2011.
Poole firm Greendale Construction Ltd has been chosen as the main contractor.
As part of the project, the 40-tonne stone Great Globe, which was erected in the late 19th Century by George Burt, owner of the Durlston Estate, has been restored.
Specialists Sue and Lawrence Kelland carried out the work last summer.