VOLCANOES, says Val Rentsch with no hint of humour, "blow your mind".

And none more so, she says, than the 400-odd volcanoes of Victoria's Western District.

They stretch from Bacchus Marsh to Mt Gambier and blew their tops as recently as 5000 years ago, with the oldest erupting roughly 350,000 years ago.

Rest assured, Val adds, they're not about to spew forth lava.

"Although a volcanologist came out last year and said Victoria was due for an eruption again some time," she says.

"I don't think were going to blow up - but I'm not a geologist.

"Seeing as we're sitting in the middle of them, I like to think they're dormant."

Val has become something of an amateur volcanologist since becoming one of the original volunteers to establish and operate the Penshurst Volcanoes Discovery Centre.

The centre, in the town near Hamilton and at the base of Mt Rouse, was established in 2003 and is run by a band of 30 volunteers.

Val says you don't have to be a lava lover to appreciate volcanoes, saying it is a rarely acknowledged fact that a vast chunk of Victoria's topography is due to our explosive history.

"It's an amazing area when you think about the different results of volcanic activity," Val says.

"Around Camperdown are high scoria cones - which are volcanoes that erupt like when you shake a bottle of soft drink or take the cork off champagne.

"Mt Rouse, Mt Elephant and Mt Leura are also scoria cones." Val says volcanoes created many of our lake craters, such as Lake Gnotuk, which is eight times saltier than the sea, and Lake Bullen Merri.

Tower Hill was formed by an explosion of hot magna under the water table that forced steam to boil up, explode and then collapse.

Val says one of the longest lava flows in the region runs from Mt Rouse to Port Fairy, where it then continues under the sea.

"This created some of the purest bluestone in the world," she says.

Val, a retired secondary school teacher, has a lifelong affinity with the region's peaks, growing up at the base of Mt William, at Willaura, and now taking daily hikes up Mt Rouse.

"We are spoilt for choice with the volcanoes in this area," she says. "They fire up your imagination, and get you hooked."