UNDERGROUND tours at the National Mining Museum have started again.
The Museum, at Overton near Grange Moor, cancelled its popular tours at the end of June owing to the threat of flooding.
But new information reveals there is no risk to the mine.
Commercial director Richard Saward said: "This is the best news.
"We are delighted that we can open the tour to the public again as we appreciate that it is the highlight of any visit to the museum.
"We would like to reassure visitors that the closure was only precautionary action."
New calculations by engineers have confirmed that if water is present in a borehole in Flockton as indicated in previous tests, it would take 31 days to reach the Museum, based at the former Caphouse Colliery.
The Museum's mine water pumping operation at Hope Pit on the museum site would be more than capable of dealing with the increased demand.
A spokesman for the museum said investigations would continue into the borehole at the centre of the decision.
He said it decided to close the underground tour even though there had not been an imminent threat to safety.