DevAdvocacy and Community
#30DayMapChallenge 2026
One feature of the app per day of the challenge, with a place for each
The day-by-day plan behind Advocacy; the post drafts and the venues per country are on their own pages.
#30DayMapChallenge 2026: one feature a day
Themes as published on 30daymapchallenge.com (checked 2026-10-04). Each day is one post with a snapshot and its shareable URL, tagged #30DayMapChallenge, each highlighting a different part of the app. Places are suggestions; prepare the URLs in a bookmarks project in October so a day takes minutes.
| Day | Theme | Feature | Map |
|---|---|---|---|
| 1 | Points | Drawing + Feature Iterator, Animation | A layer of summits as points, stepped through one by one with the iterator; the post is an animation fly-through keyed on them. |
| 2 | Lines | Contours, LRM reference | LRM contours on a hillfort or an Iron Age field system, lines following the earthworks instead of altitude. |
| 3 | Polygons | Coverage overlays | LiDAR and 3D footprints (national LiDAR, FLAI, Google 3D) over Europe: where the fine terrain is. |
| 4 | Clusters | Tells detection (beta) | Mound candidates clustering on a tell plain (Khabur basin, Syria) or a barrow cemetery in AHN. |
| 5 | Senses: Sight | Profile line of sight; sky-view factor, openness | What can be seen: a line-of-sight profile between a summit and a valley village (blocked or not, with the mast height), then how much sky each point sees in a canyon or a sunken lane. |
| 6 | Vintage | Historical timeline + Catalogs | A 19th-century Map Warper or Allmaps sheet draped on 3D terrain, then the timeline scrubbed to today. |
| 7 | 10 minute map | Featured bookmarks, Snapshot & Copy | A screen recording: open a featured bookmark, switch two modes, copy the snapshot, under 10 minutes. |
| 8 | Utopia | Threshold outline (beta) | A lake that could be: the outline of a reservoir level, or a sea-level rise contour on a coastal DEM. |
| 9 | Urban-rural | nDSM, split view | Height above ground across a city edge: buildings on one side, hedgerows and canopy on the other. |
| 10 | Prompting only | AI assistants (skill, llms.txt) | The whole map built by asking an assistant for a Terrain Viewer URL; post the prompt next to the result. |
| 11 | Senses: Sound | 3D view, negative openness | A Greek theatre (Epidaurus) or a natural amphitheatre: the bowl that carries the sound. |
| 12 | Power | Historical timeline, 2×2 grid | A dam and its reservoir filling (Grand Ethiopian Renaissance Dam), four dates side by side. |
| 13 | Interactions | Overlay split, embedding | The draggable gutter and blend handle between two DEMs, embedded as an interactive iframe in the post. |
| 14 | Borgesian map | Finest LiDAR, max zoom | IGN LiDAR HD or AHN at 50 cm, zoomed until single trees and boulders: the map as detailed as the ground. |
| 15 | Inside out | Negative openness | Valleys lit as ridges: a familiar massif rendered inside out. |
| 16 | Collaborative map | Bookmarks projects, import/export | A project built with a friend, each adding views, merged by JSON import, shared as one link. |
| 17 | Light & dark | Phong + hard shadows, Sun calculator | One valley at sunrise and sunset driven by the real date and time; or the shadow calendar of a village in a deep valley. |
| 18 | NULL | Coverage edges, no-data | Where the LiDAR stops: the seam between a national LiDAR and the global fallback, made visible with a derivative. |
| 19 | Senses: Smell | Historical timeline | A landfill growing (Bantar Gebang, Jakarta) through Wayback and Google Earth dates. |
| 20 | Hexagons | ArcticDEM via STAC, LRM / curvature | Ice-wedge polygons in Arctic permafrost: nature's near-hexagons in a 2 m DEM. |
| 21 | OpenStreetMap | OSM ELI on the timeline | The dated orthophotos mappers trace from, as ticks over one city (Brussels UrbIS 2004 to 2024). |
| 22 | Projections | Globe view | Terrain and hillshade on the globe at low zoom, against the Mercator view of the same place. |
| 23 | Senses: Taste | Aspect, slope, sun position | Vineyards: the Côte d'Or or the Douro terraces, aspect and slope explaining where the grapes go. |
| 24 | Network | LRM on national LiDAR | A Roman road network, or medieval hollow ways, appearing in Defra or AHN LiDAR. |
| 25 | Is this a map? | Non-geo relief (matcap) | A fresco or coin scan as a heightmap, shaded with matcap like a mountain range. |
| 26 | Water | River REM | Relative elevation model of a meandering river (the Mississippi, the Allier): every old channel in colour. |
| 27 | New tool | Image Georeferencer | An old photo or map georeferenced in the browser and draped on the terrain, start to finish. |
| 28 | Senses: Feeling | Profile, slope classes | How a climb feels: an elevation profile of a route with its steepest stretches coloured (Eiger north face, a classic hike). |
| 29 | Raster | DEM difference | Two surveys subtracted: a glacier's thinning or a landslide scar as a red-blue raster. |
| 30 | Pen & paper | Snapshot export | A contours + hillshade print traced by hand; post the photo next to the screen. |