Fans of the paranormal have spent their first night exploring the caves at the Devon tourist attraction, Kents Cavern.
The ghost hunters hope to raise £2,500 for charity
The group spent the night deep in the underground caves at Torquay, which are more than two million years old.
The ghost hunters were also raising funds for children's cancer charity CLIC Sargent.
"I've always been a sceptic, however I was very surprised, some of the things that I saw just cannot be explained," said James Hull from Kents Cavern.
Kents Cavern has long been rumoured to be haunted, and charity supporters braved the darkness with experts from Haunting Experiences, a South West-based paranormal group.
A Haunting Experiences spokesman said: "There was a huge amount of activity that night, much of it hard to explain; such as water dripping, people moving around or sensory deprivation in a dark, spooky place."
The cavern is the oldest recognisable human dwelling in Britain, with artefacts and remains dating back half a million years.
Mr Hull told BBC News more than 80,000 had been discovered, including bones of sabre-toothed tigers, mammoths, hyenas and wolves.
Tests showed a piece of jawbone was more than 37,000 years old
A 13,000-year-old human skull was also found in the caves, which used to be marshland and were also the site of an old Roman burial ground.
One of the caves' most famous discoveries was a piece of jaw bone which carbon tests have shown came from a neanderthal man between 37,000 and 40,000 years ago.
"It's the only place in the world where there's been continuous human activity for more than half a million years," Mr Hull said.
"So it's more than likely there could be ghosts. Some things I could explain, but there was lots I couldn't.
"The group was wearing safety helmets - some of them were moving, actually lifting up.
"I was more interested than scared and I'll have a bit more respect when I go in to the caves."