The multi-alarm blaze broke out just after midnight on Monday at the former Ponderlodge Golf Club on Shawmont Avenue in Lower Township.
Huge balls of flame consumed the building. Firefighters had to tap into a nearby lake to douse the fire.
There were no injuries.
The state had taken over the golf course to develop and environmental education center. Some of the buildings were going to be demolished.
According to Lower Township, the fire was ruled an arson. The state fire marshals office is investigating.
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