Explorers have shared images of the hidden world beneath Bendigo and Castlemaine residents' feet

There are quite a few rib-tightening spaces for explorers to crawl through as they navigate the Ajax Complex in the Castlemaine area.

“A bit compressed on the old stomach, Raymo,” someone says as dusty figures take turns to inch through a narrow “squeeze” in a thick wall of rock dividing this subterranean world from the surface.

Raymo Shaw is the founder of Victorian Historical Mine Shaft Chasers Inc, a group that abseils into historical diggings left by colonial settlers.

The group travels all over the state looking for new shafts to explore and have been publishing images and videos of recent travels through central Victoria’s mines online, including the New Prince of Wales complex near Bendigo.

It can take anywhere from one to six hours to explore a shaft and the drives that spread from it. The crew have to contend with tight spaces and huge drops.

They surveyed these places out of personal interest. Mr Shaw had visited at least 400.

“It’s highly addictive for me.”

The team now numbered 18 people and Mr Shaw said men and women from all walks of life had become mine chasers.

“It’s the explorer that comes out when we are children and is always following us as we grow up,” he said.

“I don’t know why people want to follow me down but I think it’s the chase. They want to find something down there of historical significance. It’s not just going down to have a look around.”

Mr Shaw said they were not motivated by the search for gold, which would be illegal.

Some of the most exciting moments came when the team found artifacts left behind by miners.

“Miners’ graffiti is a really cool thing. Generally they’ll write their name and possibly the date … that is absolutely fantastic,” Mr Shaw said.

“One of the coolest things we’ve ever found was a copy of the Bendigo Advertiser dated from 1889.”

Mr Shaw recommended people exercise caution around mines-shafts and leave exploration to the experts.

Asked whether he ever felt claustrophobic in the tight spaces he explored, Mr Shaw said “no”.

“I have a gas monitor and that tells us if something bad is going to happen. Sometimes we have to pump air into places but generally I find those old-timers who mined these areas knew what they were doing.”