DEFA seeks information on how they're used
A new survey is asking the public whether government should still be responsible for the maintenance of Glens.
The Department of Environment, Food and Agriculture launched it at last weekend's Royal Agricultural Show, and says it's already received many responses.
The Island's 18 National Glens cover about 1,000 acres (4 km²).
Around 850,000 visits are made every year - but DEFA wants to know how the spaces are actually used by residents and tourists alike.
The results of the survey, it says, will be used to plan 'sensitive' future development and measure investment.
Forestry officials will also be out and about in the Glens over the next few weeks interviewing people onsite.
You can take the questionnaire for yourself by clicking here.