Seven houses have been evacuated after a sinkhole "with an unknown depth" appeared in gardens.
Emergency crews were called to the 66ft (20m) wide hole in Magdalen's Road, Ripon, on Tuesday night, North Yorkshire Fire and Rescue Service confirmed.
A spokesman said: "Two fire crews and an officer from Ripon attended a sinkhole that had appeared at the rear of two properties.
"There were no injuries but seven properties were evacuated.
"The hole measured approx 20m (66ft) by 10m (33ft) with an unknown depth.
"We are re-attending the incident this morning with several other agencies who attended during the night."
The Ripon area is prone to sinkhole activity and this incident is close to where another opened up beneath a 100-year-old building in Magdalen's Close in 2014, leaving it in a precarious state.
One resident took to social media to say his garden had disappeared.
He said: "30ft deep sink hole enveloping the back garden occurred at 10.30. Been told to leave the house for the night."
And he added: "Yeah, they've evacuated our row. Swallowed the garden so 'twill be interesting in light."
Sinkholes are relatively common in Ripon and are usually caused by the dissolution of thick gypsum deposits beneath the area.
After the 2014 partial house collapse, the British Geological Survey (BGS) said gypsum under the town had dissolved to form a maze-like cave system.
It said in a report that sinkholes appeared in Ripon every two or three years in the 1980s and 1990s but there had not been any reported in the seven years before the 2014 event.
The BGS said there were a number of possible triggering mechanisms, relating to action of water underground.