Chief executive Malcolm Snow said parking inspectors would target cars parked on open or landscaped spaces on national land over the next few weeks including on weekends.

He said it was illegal to park cars on paths, grassed areas and paved surfaces around the capital's national institutions, including Commonwealth Park, Old Parliament House Gardens, East and West Lawns, and Kings Park.

Mr Snow said parking in these areas put an increasing number of Canberrans at risk as more and more people descended on the parliamentary triangle to enjoy the warm weather.

"With pedestrians, children and cyclists also using these areas, there is a serious public safety risk if this practice continues," he said.

"Many of the cars are parked close to access paths, playgrounds and barbeque facilities.

"Young children should be able to run around these open spaces, or cyclists to use the shared paths without the risk of being injured from a reversing car."

Mr Snow said drivers often parked outside designated spaces to capture shade from nearby trees.

He said parking in these areas not only put people's safety at risk but could also damage vegetation.

"Vehicles driving and parking on open space can also cause damage to the landscape such as lawns, tree roots, and irrigation systems," he said.

"Replacing plants, grass and sprinkler heads diverts resourcing away from maintaining other areas of the central national area. Mature trees declining as a result of soil compaction from heavy vehicles is a more difficult issue to remedy.

"People come to these spaces because of the beautiful setting however, because of their thoughtless actions the amenity is destroyed."

Mr Snow urged drivers to park in the correct spot.

"There are ample car spaces available for motorists. I am encouraging Canberrans to walk that little bit longer, so everyone can enjoy our beautiful parks and open spaces in safety," he said.

The NCA manages the pay parking arrangements on national land in Canberra on behalf of the Australian Government, including the enforcement of breaches of parking regulations.