Symbols for points of interest are not "baked in" to map tiles. Based on feedback from Park Tiles stakeholders, we've determined that the best practice is to support points of interest as an interactive overlay, managed at the application level. This approach provides several advantages:
- Individual parks and programs can determine which points of interest to feature in their own web map applications, and how those points of interest are symbolized.
- Points of interest added as an overlay can be interactive, revealing information to the user with a hover or click, and again, this interactivity and the information displayed can be determined by individual parks and programs to best suit their needs.
- Removing points of interest from the basemap eliminates overlaps and visual conflicts with interactive overlays.
One frequently-used application of Park Tiles is nps.gov. In this application, points of interest housed in the NPS point of interest national dataset can be toggled on/off and popups display when points of interest are selected. POITYPE values associated with each point of interest determine their map symbols. A description of this application's point of interest overlay configuration follows below.
Overview
In the POI overlay layer, POIs are displayed as symbols from the NPMap Symbol Library inside teardrop markers. POIs appear progressively as the user zooms in. Major POI types begin to appear at small zoom levels and all POI types appear by zoom level 16. POIs with no corresponding symbol in our symbol library display as a small black dot. All types are clickable, and clicking on a POI reveals a popup that displays the POI's name and type.
Default configuration
The display of each POI type is controlled by a simple JSON file that dictates which type corresponds to which symbol, and at what zoom level that symbol should appear. Here are the default settings:
| POI type | Symbol name | Symbol | Minimum zoom | Priority |
|---|---|---|---|---|
| entrance station | entrance-station |
|
IF min_zoom_poly+6<16 THEN min_zoom_poly+6 ELSE 16
|
1 |
| information | information |
|
IF min_zoom_poly+6<16 THEN min_zoom_poly+6 ELSE 16
|
1 |
| visitor center | visitor-center |
|
IF min_zoom_poly+5<16 THEN min_zoom_poly+5 ELSE 16
|
1 |
| campground | campground |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
2 |
| lodge | lodging |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
2 |
| lodging | lodging |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
2 |
| ranger station | ranger-station |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
2 |
| rv campground | rv-campground |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
2 |
| fee booth | entrance-station |
|
IF min_zoom_poly+6<16 THEN min_zoom_poly+6 ELSE 16
|
2 |
| food service | food-service |
|
IF min_zoom_poly+8<16 THEN min_zoom_poly+8 ELSE 16
|
3 |
| gas station | gas-station |
|
IF min_zoom_poly+8<16 THEN min_zoom_poly+8 ELSE 16
|
3 |
| picnic area | picnic-area |
|
IF min_zoom_poly+8<16 THEN min_zoom_poly+8 ELSE 16
|
3 |
| trailhead | trailhead |
|
IF min_zoom_poly+8<16 THEN min_zoom_poly+8 ELSE 16
|
3 |
| gift shop | souvenir |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
3 |
| store | store |
|
IF min_zoom_poly+7<16 THEN min_zoom_poly+7 ELSE 16
|
3 |
| beach | beach-access |
|
16 | 3 |
| bookstore | bookstore |
|
16 | 3 |
| bus stop / shuttle stop | bus-stop |
|
16 | 3 |
| cabin | shelter-cabin |
|
16 | 3 |
| campsite | campsite |
|
16 | 3 |
| cinema | theater |
|
16 | 3 |
| emergency telephone | emergency-telephone |
|
16 | 3 |
| ferry terminal | vehicle-ferry |
|
16 | 3 |
| first aid station | first-aid |
|
16 | 3 |
| historic district | historic-feature |
|
16 | 3 |
| historic marker | historic-feature |
|
16 | 3 |
| historic site | historic-feature |
|
16 | 3 |
| horse camp | horseback-riding |
|
16 | 3 |
| hospital | hospital |
|
16 | 3 |
| library | library |
|
16 | 3 |
| lighthouse | lighthouse |
|
16 | 3 |
| marina | marina |
|
16 | 3 |
| memorial | statue |
|
16 | 3 |
| metro stop / subway entrance | letter-m |
|
16 | 3 |
| monument | statue |
|
16 | 3 |
| museum | museum |
|
16 | 3 |
| overlook | scenic-viewpoint |
|
16 | 3 |
| post office | post-office |
|
16 | 3 |
| restroom | restrooms |
|
16 | 3 |
| self guiding trail | self-guiding-trail |
|
16 | 3 |
| shelter | shelter |
|
16 | 3 |
| telephone | telephone |
|
16 | 3 |
| viewpoint | scenic-viewpoint |
|
16 | 3 |
| waterfall | waterfall |
|
16 | 3 |
| airport | airport |
|
16 | 4 |
| amphitheater | amphitheater |
|
16 | 4 |
| atm | atm |
|
16 | 4 |
| bicycle trail | bicycle-trail |
|
16 | 4 |
| boat launch | boat-launch |
|
16 | 4 |
| canoe / kayak access | canoe-access |
|
16 | 4 |
| cave entrance | cave |
|
16 | 4 |
| cross-country ski trail | cross-country-ski-trail |
|
16 | 4 |
| dam | dam |
|
16 | 4 |
| directional sign | sign |
|
16 | 4 |
| downhill ski trail | downhill-skiing |
|
16 | 4 |
| dump station | sanitary-disposal-station |
|
16 | 4 |
| dumpster | trash-dumpster |
|
16 | 4 |
| fishing | fishing |
|
16 | 4 |
| floating restroom | restrooms |
|
16 | 4 |
| food box / food cache | food-cache |
|
16 | 4 |
| fountain | drinking-water |
|
16 | 4 |
| four-wheel drive trail | four-wheel-drive-road |
|
16 | 4 |
| garage | mechanic |
|
16 | 4 |
| gateway sign | sign |
|
16 | 4 |
| gazebo | shelter |
|
16 | 4 |
| golf course | golfing |
|
16 | 4 |
| historic building | historic-feature |
|
16 | 4 |
| historic cabin | historic-feature |
|
16 | 4 |
| historic mine | historic-feature |
|
16 | 4 |
| historic ruins | historic-feature |
|
16 | 4 |
| historic ship | historic-feature |
|
16 | 4 |
| horseback riding | horseback-riding |
|
16 | 4 |
| hut | shelter |
|
16 | 4 |
| ice rink | ice-skating |
|
16 | 4 |
| information board | sign |
|
16 | 4 |
| information map | sign |
|
16 | 4 |
| interpretive exhibit | interpretive-exhibit |
|
16 | 4 |
| laundry | laundry |
|
16 | 4 |
| litter receptacle | litter-receptacle |
|
16 | 4 |
| mailbox | post-office |
|
16 | 4 |
| motorcycle trail | motor-bike-trail |
|
16 | 4 |
| motorized trail | four-wheel-drive-road |
|
16 | 4 |
| non-motorized trail | trailhead |
|
16 | 4 |
| parking lot | parking |
|
16 | 4 |
| pavilion | shelter |
|
16 | 4 |
| playground | playground |
|
16 | 4 |
| potable water | drinking-water |
|
16 | 4 |
| primitive camping | campsite |
|
16 | 4 |
| radiator water | radiator-water |
|
16 | 4 |
| recycling | recycling |
|
16 | 4 |
| regulatory sign | sign |
|
16 | 4 |
| sailing | sailing |
|
16 | 4 |
| scuba diving | scuba-diving |
|
16 | 4 |
| sculpture | statue |
|
16 | 4 |
| seaplane base | sea-plane |
|
16 | 4 |
| showers | showers |
|
16 | 4 |
| sledding | sledding |
|
16 | 4 |
| snowmobile trail | snowmobile-trail |
|
16 | 4 |
| spring | spring |
|
16 | 4 |
| stable | stable |
|
16 | 4 |
| swimming area | swimming |
|
16 | 4 |
| tower | lookout-tower |
|
16 | 4 |
| trail marker | sign |
|
16 | 4 |
| trail register | trailhead |
|
16 | 4 |
| tunnel | tunnel |
|
16 | 4 |
| webcam | webcam |
|
16 | 4 |
| wheelchair accessible | wheelchair-accessible |
|
16 | 4 |
| wi-fi | wi-fi |
|
16 | 4 |
| windsurfing area | wind-surfing |
|
16 | 4 |
| wreck | historic-feature |
|
16 | 4 |
| zebra mussel decontamination station | zebra-mussel-decontamination-station |
|
16 | 4 |
| all-terrain vehicle trail | all-terrain-trail |
|
16 | 5 |
| trail sign | sign |
|
16 | 5 |
| mile marker | sign |
|
16 | 5 |
| flag pole | flagpole |
|
16 | 5 |
| campfire ring | campfire |
|
16 | 5 |
| administrative office | dot |
|
16 | 5 |
| airstrip | dot |
|
16 | 5 |
| anchorage | dot |
|
16 | 5 |
| apartments | dot |
|
16 | 5 |
| arch | dot |
|
16 | 5 |
| arroyo | dot |
|
16 | 5 |
| athletic field | dot |
|
16 | 5 |
| backcountry ski trail | dot |
|
16 | 5 |
| barn | dot |
|
16 | 5 |
| basin | dot |
|
16 | 5 |
| battlefield | dot |
|
16 | 5 |
| battlefield marker | dot |
|
16 | 5 |
| bay | dot |
|
16 | 5 |
| bench | dot |
|
16 | 5 |
| bike rack | dot |
|
16 | 5 |
| boat dock | dot |
|
16 | 5 |
| boat storage | dot |
|
16 | 5 |
| bridge | dot |
|
16 | 5 |
| brochure box | dot |
|
16 | 5 |
| building | dot |
|
16 | 5 |
| building under construction | dot |
|
16 | 5 |
| bunker | dot |
|
16 | 5 |
| buoy | dot |
|
16 | 5 |
| canal | dot |
|
16 | 5 |
| cannon | dot |
|
16 | 5 |
| canyon | dot |
|
16 | 5 |
| canyoneering route | dot |
|
16 | 5 |
| cape | dot |
|
16 | 5 |
| cathedral | dot |
|
16 | 5 |
| cemetery / graveyard | dot |
|
16 | 5 |
| chapel | dot |
|
16 | 5 |
| church | dot |
|
16 | 5 |
| cliff | dot |
|
16 | 5 |
| climbing route | dot |
|
16 | 5 |
| commercial building | dot |
|
16 | 5 |
| cultural landscape | dot |
|
16 | 5 |
| desert | dot |
|
16 | 5 |
| detached home | dot |
|
16 | 5 |
| dog sled trail | dot |
|
16 | 5 |
| dormitory | dot |
|
16 | 5 |
| dune | dot |
|
16 | 5 |
| dyke (levee) | dot |
|
16 | 5 |
| education center | dot |
|
16 | 5 |
| electric vehicle parking | dot |
|
16 | 5 |
| fence | dot |
|
16 | 5 |
| fire hydrant | dot |
|
16 | 5 |
| fire station | dot |
|
16 | 5 |
| fish cleaning | dot |
|
16 | 5 |
| fish hatchery | dot |
|
16 | 5 |
| forest | dot |
|
16 | 5 |
| fortification | dot |
|
16 | 5 |
| fumarole | dot |
|
16 | 5 |
| garden | dot |
|
16 | 5 |
| gate | dot |
|
16 | 5 |
| geyser | dot |
|
16 | 5 |
| glacier | dot |
|
16 | 5 |
| grassland | dot |
|
16 | 5 |
| grave | dot |
|
16 | 5 |
| greenhouse | dot |
|
16 | 5 |
| grill | dot |
|
16 | 5 |
| grove | dot |
|
16 | 5 |
| harbor | dot |
|
16 | 5 |
| headquarters | dot |
|
16 | 5 |
| hot spring | dot |
|
16 | 5 |
| house | dot |
|
16 | 5 |
| industrial building | dot |
|
16 | 5 |
| island | dot |
|
16 | 5 |
| isthmus | dot |
|
16 | 5 |
| junction | dot |
|
16 | 5 |
| lake | dot |
|
16 | 5 |
| landing strip | dot |
|
16 | 5 |
| lava | dot |
|
16 | 5 |
| locale | dot |
|
16 | 5 |
| lock | dot |
|
16 | 5 |
| military area | dot |
|
16 | 5 |
| mooring | dot |
|
16 | 5 |
| mountain pass (saddle / gap) | dot |
|
16 | 5 |
| mud pot | dot |
|
16 | 5 |
| natural feature | dot |
|
16 | 5 |
| office | dot |
|
16 | 5 |
| oilfield | dot |
|
16 | 5 |
| park | dot |
|
16 | 5 |
| patrol cabin | dot |
|
16 | 5 |
| peak | dot |
|
16 | 5 |
| picnic table | dot |
|
16 | 5 |
| pillar | dot |
|
16 | 5 |
| plain | dot |
|
16 | 5 |
| plateau | dot |
|
16 | 5 |
| point of interest | dot |
|
16 | 5 |
| police | dot |
|
16 | 5 |
| populated place | dot |
|
16 | 5 |
| prairie | dot |
|
16 | 5 |
| public building | dot |
|
16 | 5 |
| quarry (mine) | dot |
|
16 | 5 |
| ranch | dot |
|
16 | 5 |
| rapids | dot |
|
16 | 5 |
| reef (bar) | dot |
|
16 | 5 |
| reserve | dot |
|
16 | 5 |
| reservoir | dot |
|
16 | 5 |
| residential building | dot |
|
16 | 5 |
| retail building | dot |
|
16 | 5 |
| ridge | dot |
|
16 | 5 |
| roadside pullout | dot |
|
16 | 5 |
| rock formation | dot |
|
16 | 5 |
| row house | dot |
|
16 | 5 |
| school building | dot |
|
16 | 5 |
| sea | dot |
|
16 | 5 |
| shaft (mine) | dot |
|
16 | 5 |
| shed | dot |
|
16 | 5 |
| shoal (bar) | dot |
|
16 | 5 |
| snowshoe trail | dot |
|
16 | 5 |
| static mobile home | dot |
|
16 | 5 |
| steps | dot |
|
16 | 5 |
| strait (channel) | dot |
|
16 | 5 |
| stream | dot |
|
16 | 5 |
| swamp | dot |
|
16 | 5 |
| totem pole | dot |
|
16 | 5 |
| traffic signals | dot |
|
16 | 5 |
| train station | dot |
|
16 | 5 |
| tree | dot |
|
16 | 5 |
| turning circle | dot |
|
16 | 5 |
| university building | dot |
|
16 | 5 |
| valley | dot |
|
16 | 5 |
| volcano | dot |
|
16 | 5 |
| warehouse | dot |
|
16 | 5 |
| water access | dot |
|
16 | 5 |
| water well | dot |
|
16 | 5 |
| weather shelter | dot |
|
16 | 5 |
| wetland | dot |
|
16 | 5 |
| windmill | dot |
|
16 | 5 |
| woods | dot |
|
16 | 5 |
Minimum zoom is used to determine at which zoom level a symbol begins to appear. To accommodate parks of different sizes, our default settings use a formula to determine minimum zoom for major POI types. The formula produces a value that varies with park size (determined by a park's min_zoom_poly value – an internal number used to control when parks are displayed as polygons instead of points). This formula ensures that larger parks will have visitor centers appear early while appearing later in smaller parks.
Custom configuration
We built our default POI overlay with customization in mind. We are currently working on an interface to allow parks to customize exactly which POIs display, and at what zoom levels they appear. We will update this document with more information once this tool has been developed.