                "type": "Point",
                    "coordinates": [-121.354465, 40.488737]
                }
            }]
        }
    });

    map.addLayer({
        "id": "park-boundary",
        "type": "fill",
        "source": "national-park",
        "paint": {
            "fill-color": "#888888",
            "fill-opacity": 0.4
        },
        "filter": ["==", "$type", "Polygon"]
    });

    map.addLayer({
        "id": "park-volcanoes",
        "type": "circle",
        "source": "national-