Families in about 20 properties have been evacuated from their homes as fire crews tackled a large mountain blaze.
North Wales Fire and Rescue Service had 30 firefighters at Blaenau Ffestiniog, Gwynedd, overnight.
Eyewitness Chris McPhail said: “As I was driving up I could just see the glow and a load of smoke. It just looked like a volcano.”
The alarm was raised just before 20:30 BST on Monday, with residents asked to leave in the early hours of Tuesday.
BBC Wales employee Laura Raymond said she was woken by firefighters “smashing open” fire hydrants at about 03:00.
“The hill was literally glowing from behind,” she said.
The blaze is thought to have started behind quarry workings in an area overlooking the town called Garreg Ddu – Black Rock.
“Black Rock is like a huge gigantic lump of coal, with burning embers,” said Ms Raymond.
“We’ve been well looked after and the crews have done an amazing job. We’re just so thankful because the crews have directed it away from the houses.”
Police have closed part of Church Street through the town as fire crews continue to tackle the flames – but it is expected to reopen soon.
Teams from Dolgellau, Porthmadog, Blaenau, Harlech, Nefyn and Johnstown have been at the scene, with an aerial platform called in from Bangor.
Many of the evacuated residents spent the night in a cafe, including Jackie Brunger.
She told BBC Radio Wales’ Good Morning Wales she was unaware of the blaze until fire crews arrived.
“It was just glowing orange and it was absolutely frightening – I’ve never seen anything like it. We were told to get away as soon as we could, so we took our car and went to the cafe.
“There was ash and bits of flame coming down. How far it has spread, so quickly – it was frightening.”
Sue Roberts opened up DeNiros cafe for those told to leave their homes, and helped keep fire crews and police teams fed during the night.
“It’s been a bit busy,” she joked. “It looked quite spectacular when you think about it.”
People have now started returning to their homes in the area, with firefighters winding down operations.
Councillor Annwen Daniels said she expected the fire service to have a presence in the town for the rest of the day.
She said she thought Gwynedd Council would work closely with North Wales Fire and Rescue Service to prevent a repeat of the events on Monday evening.
“Blaenau Ffestiniog is infamous for being a wet place – but when you want the rain, it isn’t coming,” she added.