Scientists have used 3D modelling to help them better understand an extinct volcano in the north west Highlands.
The 58 million-year-old site in Ardnamurchan is well known to geologists interested in the study of rocks and structures in volcano cores.
Researchers led by Sweden's Uppsala University have challenged a long-standing theory that it had three magma chambers.
They suggest it only had one large chamber.
According to measurements from the 3D modelling, it was less than a mile (1.5km) below today's land surface and was more than three miles (6km) wide.
Researchers from St Andrews University in Fife, Durham University in north east England and also some from Canada were involved in the new study.
Dr Steffi Burchardt, of Uppsala University, said: "It came as a bit of a surprise to us that there is still so much to learn from a place that has received so much attention by geologists."
The senior lecturer added: "These types of magma chambers are known to exist, for example, within volcanoes in Iceland have have been detected in the North Sea bedrock."