The boys, aged six to 22, have been working shoulder to shoulder for two years building the dirt bike ramps on a vacant block of land near Aspinall Street.

Using their hands, a broken shovel, scraps of timber and posts, the boys moulded and shaped a course and created a popular meeting place after school.

Parents of younger boys came along to watch their kids join the fun-filled afternoons.

But after a complaint, a Department of Territory and Municipal Services work crew arrived early on Tuesday morning with a front-end loader and flattened the course.

Watson residents Nancy Jones and Steve Coelli are dismayed the boys' ingenuity was snuffed out on the eve of the Christmas holidays.

''There needs to be a point where we allow our children to be children,'' Ms Jones said.

''I have a background in child psychology. This really is very sad, very sad for the young boys.

''It was a meeting place for young men, it was secret men's business. They were all budding civil engineers.

''More often than not there were parents there, more often than not there were young boys there so they [older boys] minded their language.

''They helped the littlies, took them on their small bikes and guided them over the jumps and had little jumps for the littlies.''

Mr Coelli, a school teacher, said boys digging and packing down dirt reminded him of his tree cubby and billycart days. He said they could find any number of windows to break, televisions to steal or could grow fat in front of computer screens.

One furious parent admitted that the track was dodgy, but said ''babies' parks'' did not fulfil a boy's need for adventure.

Ms Jones said she understood the Government was preventing accidents, but she, too, was at risk when she flew kites on vacant land, as were people walking their dogs.

''There is always a chance that can happen, it doesn't matter where you are, she said. ''They're all armed with mobile phones, they're all mature enough to know what to do if something happens.''

A department spokesman said the jumps were illegally constructed, were inspected and deemed unsafe and inappropriate, after a resident complained.

Four pallets, seven timber boards and an old sign post were removed.

For more, pick up a copy of today's Canberra Times