title: icons must be visible at different view level
body: <p>I use openlayers3 to build an application</p>
  
  <p>I would like to change the zoomlevel icons are visible at</p>
  
  <p><a href="https://bestofosm.org/?lon=4.0798&amp;lat=50.9136&amp;zoom=15#interesting-het-loo-garden" rel="nofollow noreferrer">https://bestofosm.org/?lon=4.0798&amp;lat=50.9136&amp;zoom=15#interesting-het-loo-garden</a></p>
  
  <p>for example</p>
  
  <p>if you go to London you see airports are visible at zoomlevel 10</p>
  
  <p>lets say I want all touristic icons visible at zoomlevel 10
  and airport icons at zoomlevel 15
  is this possible?</p>