<!DOCTYPE html>
<html>
<head>
    <title>Grand Rapids Park and Recreation Investments</title>
</head>
<body style="margin:0px;padding:0px;overflow:hidden">
    <center>
        <div style="position: relative; float: right;">
            <iframe src="https://render.githubusercontent.com/view/geojson?url=https://raw.githubusercontent.com/friendlycode/gr-parks/gh-pages/parks.geojson" frameborder="0" style="overflow:hidden;overflow-x:hidden;overflow-y:hidden;height:550px;width:1000px;"></iframe>
        </div>
    </center>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
    <title>Grand Rapids Park and Recreation Investments</title>
</head>
<body style="margin:0px;padding:0px;overflow:hidden">
    <a href="map.html" target="_blank">Alternate version</a>
    <center>
        <div style="position: relative; float: right;">
            <iframe src="https://render.githubusercontent.com/view/geojson?url=https://raw.githubusercontent.com/friendlycode/gr-parks/gh-pages/parks.geojson" frameborder="0" style="overflow:hidden;overflow-x:hidden;overflow-y:hidden;height:550px;width:1000px;"></iframe>
        </div>
    </center>
</body>
</html>

Add link to new custom-javascript version
Add link to new custom-javascript version

The other version uses the leaflet map-rendering engine directly in order to access the map's popups and the geojson data.