The Ranger uranium mine next to Kakadu has closed after 40 years of operation.
The mine is owned by Energy Resources of Australia and neighbours Kakadu National Park.
The Australian Conservation Foundation welcomed the closure and nuclear campaigner David Sweeney said attention needs to be turned to the mine site's environmental rehabilitation.
"This is a very good day for Kakadu, the Northern Territory and Australia," Mr Sweeney said.
"The Ranger mine has generated controversy, headlines and heartache for four decades.
"The focus must now be on ERA and parent company Rio Tinto doing comprehensive and credible site rehabilitation and supporting the transition to a post-mining regional economy."
Mr Sweeney repeated calls made last year by ACF, urging ERA and Rio Tinto to change their rehab plan.
He said the plan will damage the environmental integrity of Kakadu.
"Plans for cleaning up the site of the Ranger mine are being hampered by an unrealistic rehabilitation time frame, funding uncertainty, and fears about a tailings dam leaking toxic contaminants into the surrounding national park."
The closure means Ranger's township Jabiru will no longer be a mining community.
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