A mountain range nicknamed 'Mordor-under-the-sea' has been discovered off the southern coast of Australia.
Undersea volcanic eruptions around 35 million years ago created the Tolkienesque landscape, scientists say.
"By using data acquired as part of oil exploration efforts, we have been able to map these ancient lava flows in unprecedented detail, revealing a spectacular volcanic landscape that bring to mind illustrations from Lord of the Rings," said Dr Nick Schofield of the University of Aberdeen's School of Geosciences.
"Submarine lava ﬂows are inherently more difﬁcult to study than their counterparts on the Earth's surface due to their inaccessibility, and the technology we have used is similar in many ways to what is used to produce ultrasound images of babies, but for the Earth."
In all they found 26 buried lava flows up to 34km long and 15km wide. The tallest volcanoes rose more than 600m, but are buried in sediment, below the seabed.
"We have a unique insight into a landscape that has remained hidden for millions of years, highlighting the growing importance of seismic data in studying submarine volcanism."
The discovery comes just days after scientists said the eruption of a little-known undersea volcano off the coast of the North Island was probably the biggest the world's seen in the last 100 years.
Researchers from the University of Adelaide, University of Aberdeen and Commonwealth Scientific and Industrial Research Organisation contributed to the research, published in journal Geochemistry, Geophysics, Geosystems.