The vandals ripped out several bluestones and graffitied the walls of the culvert, which spans a gully in the Bendigo Regional Park, off of Wattle Street near the Spring Gully Reservoir.

The culvert could date back to the 1860s, National Trust Bendigo branch president Peter Cox said.

The area is popular with walkers and cyclists and several unofficial tracks lead down into the gully and through the tunnel.

Riding and walking through the culvert is not permitted, Parks Victoria district manager Peter Foster said.

"Temporary barriers will soon be installed to reduce access," Mr Foster said.

Parks Victoria is also considering future works to "modify" access, he said.

Story continues below map (pin denotes a nearby street, not the location of the culvert)

The Bendigo Mountain Bike Club supports blocking access, despite proposing a new cycling track through the culvert back in 2015, secretary Barry Floyd said.

"It's fine - we support that. We work with Parks Victoria and while we like to see them consider trail options we understand why they want to protect that asset," he said.

If a trail does one day pass under the culvert the club hopes for works to make sure the structure's integrity is protected, Mr Floyd said.

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The National Trust's Bendigo branch wants heritage protection for the site, which does not appear to have been identified in previous historical documents or studies, Mr Cox said.

"Locals have known about it for years but it's not until people speak out about these issues (with vandalism) that we can do something about it," Mr Cox said.

Former land use planner Norm Stimson inspected the culvert in 2018 and believes it could have once been part of a road that once ran through what is now parkland.

Mr Cox is open to partnering with Parks Victoria and groups that regularly use the park to protect the site's heritage.

"These things are preserved when we have strong partnerships," Mr Cox said.

Parks Victoria is planning to carry out repair works by spring, Mr Foster said.

"This will include repairs to the stonework of the culvert to ensure the integrity of the structure," he said.

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