Several offers have been received for the former Lake Alice psychiatric hospital near Marton.
Tenders closed on Friday and real estate agency Property Brokers says there has been strong interest.
The hospital closed in 1999 but a previous attempt to develop it failed.
Most of the 56-hectare property has been turned into a farm, but various options have been mooted for the remaining buildings, from a backpackers hostel to a theme park.
Currently for sale are the water tower and a two-hectare block, including the 24-room former administration unit and a four-bedroom house.
