Residents in the eastern Chinese city of Huanshan were mystified when an enormous city rose over the city's skyline on a misty evening earlier this month.
The giant mirage complete with tall buildings, mountains and trees appeared across the skyline after heavy downpour and humid conditions along the Xin'an River.
As mist settled over the river, the life-size city appeared from nowhere, leading residents to wonder if the vision was a "vortex" to a lost civilisation.
"It's really amazing, it looks like a scene in a movie, in a fairlyland," one resident was quoted by the Daily Mail as saying.
She said that a number of similar sights had been seen recently although this one was the most spectacular.
The mysterious city vanished just as quickly as it had appeared. Scientists have since rejected the vortex theory and say the incredible sight was a mirage.
A mirage is an optical illusion in which distant objects are reflected by a layer of hot air just above ground level.
Mirages occur naturally when moisture in the air rises above the temperature of water below.