A couple has made a startling discovery under their property as they prepared to sell it.
Suzanne and James Brierley bought their home in the US state Oregon in 2017 and at the time the realtor said there was a small cave underneath the home.
However that small cave is actually a huge lava tube that is so large, even when standing they cannot touch the ceiling.
"I was really shocked by how big it was," Mr Brierley told KTVZ.
"As I bent down and went in I didn't realise how big."
He went on to describe it as a gift he and his wife didn't even know they had.
Experts said the lava tube under the Brierley's home was so large there were still unexplored areas the couple was yet to discover, according to Fox News.
The couple is still selling their home in Bend, Oregon, and they hope the future owners will preserve the tube.
Science Direct explains lava tubes are by-products of the volcanic processes and can be found throughout the world.
"They form either as the result of surface cooling of lava flows or the result of sequential lava flows, with later flows going underneath the older ones and cavities by a process called inflation," Science Direct explained.
"Kazumura Cave in Hawaii is the longest known lava tube, with 65km of passage and 101 entrances, and rarely, if ever, is more than 10 metres below the surface."
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