MapTools
NOV04DAY 04 / 30

#30DayMapChallenge 2026

Clusters

Find where things gather — and why.

4 map ideas4 tools3 data sources1 practical tip
01

AI-ASSISTED · EDITOR-REVIEWED

Theme brief

Clusters can be visible groups, statistical hotspots or simply markers combined for legibility. Be explicit about which meaning you use: a heatmap is an exploratory surface, while a formal hotspot analysis makes a stronger claim that needs method and scale.

Official prompt

“Clusters of something. Hotspots, groups, things that gather together.”

30DayMapChallenge 2026
02

WAYS IN

Four map ideas

  1. 01

    Find clusters of bird observations and compare them with protected land.

  2. 02

    Map collision hotspots while separating exposure from incident counts.

  3. 03

    Reveal restaurant districts by cuisine rather than treating all venues alike.

  4. 04

    Compare marker clustering with a density surface at several zoom levels.

03

IN THE DIRECTORY

Recommended tools

kepler.gl

Provides fast clustering, hexbin and heatmap layers for large point tables.

Open source · View details

QGIS

Supports DBSCAN, heatmaps and formal spatial statistics in one workflow.

Open source · View details

Foursquare Spatial Studio

Good for browser-based exploration of dense location data.

Freemium · View details

Leaflet

A flexible base for interactive marker clusters when you are comfortable with code.

Open source · View details
04

START WITH A CLEAR LICENSE

Data sources

GBIF occurrence records

Filter by license and cite the download DOI when available.

 CC0, CC BY or CC BY-NC per record OpenStreetMap points of interest

Query amenities, shops and other tagged places with Overpass Turbo.

 ODbL 1.0 · attribution required Municipal or regional open-data portal

Look for incident, environment, facility or sensor data with clear metadata.

 Varies by publisher

Licenses are a planning aid, not legal advice. Check the source record and version you actually download; terms can vary within a catalog.

05

BEFORE YOU EXPORT

Cartography check

Change the radius or zoom. If the story changes completely, show that sensitivity instead of presenting one setting as inevitable.

06

COMMUNITY MAPS

Selected work

Selections begin after this theme closes.

First participate officially by posting publicly with #30DayMapChallenge. You can then suggest that original post for our independent MapTools picks. We link to the source, credit every author and use images only with permission.

Suggest for MapTools picks