The Fenwick Eccles programme is reclaiming a 35ha site previously occupied by the Fenwick, Eccles and West Holywell collieries.
North Tyneside Council brought in contractors Carillion Civil Engineering last year to work on the project, which was paid for with £7m from the Homes & Communities Agency (HCA).
HCA investment and regeneration manager Martin Boys said: "The project has transformed a health and safety hazard with underground combustion into a place local people can enjoy safely.
"The focus at the Fenwick site has been on making safe the spoil heap from the former Backworth Colliery, where we found temperatures in excess of 1,000 degsC due to a process of combustion."
After stabilising the soft slurry found in lagoons within the heap, more than 120,000cu m of material has been dug out and cooled, before being returned to the heap and compacted to reduce the likelihood of further combustion.
At West Holywell the two former mineshafts have been capped, old buildings demolished and fly-tipping cleared, allowing fencing and landscaping to take place.