Firefighters battled overnight to control a huge gorse fire above Llangollen.
Dozens of callers contacted North Wales Fire Service reporting the bracken blaze at around 2248GMT.
It took fire crews until the early hours of Wednesday morning to control the 1,000 square metre blaze.
Three fire engines from Llangollen and Wrexham were sent to deal with the incident.
"The fire was above Rock Quarry in Llangollen," said a fire service spokeswoman.
"The cause of that was discarded smoking material - a cigarette or a match," she added.
Two more fire engines were sent to the other side of the Llangollen when a second blaze was reported to fire control ten minutes later at 2258GMT.
Both fires were later brought under control.