Miami-Dade County’s parks system, the third largest in the country, is today a collection of often-dazzling islands scattered across the county’s far-flung suburbs, in many cases reachable only by automobile.

But imagine someday riding your bicycle from the Miami Circle through Brickell and Coconut Grove, out to Crandon Park or down to the Charles Deering Estate or Biscayne National Park and then out west to Everglades National Park, all on marked, landscaped, tree-shaded trails and greenways.

That’s the ambitious vision behind a push to create a new Open Space Master Plan for the county: alluring links that make it possible to bike, hike, paddle or jog from neighborhood to county park to national, state or municipal parks — strands in a subtropical version of Boston’s famed Emerald Necklace of parks.