Toggle layers to add geological context. Layers are fetched live when enabled. Synced with the "Quick Layers" panel on the map. Both control the same layers.
Know if a candidate is on accessible public land before you hike to it.
Add map layers from other sources. Choose a preset below or paste a tile URL.
+ Add a layer
Drop a GeoTIFF DEM or LAS/LAZ point cloud to analyse without auto-download.
.tif .tiff .las .laz
Upload two DEMs of the same area (different dates). New or deepened depressions between surveys are flagged as high-priority cave candidates.
Queue multiple areas for overnight processing. Draw each area, configure settings, then click "Add to Queue". When ready, start all jobs.
1. Pick your area — Click Rectangle or Polygon and draw on the map where you want to search for caves. Stick to areas under 25 km² for fast results.
2. Click Find Caves — The app downloads elevation data and runs 6 detection algorithms automatically. This takes 1-5 minutes depending on area size.
3. Review results — Candidates appear as colored markers on the map, ranked by confidence score. Click any marker to see details. Higher scores = more likely to be real caves.
4. Export for field use — Download results as GPX (for GPS devices) or KML (for Google Earth) from the Results tab.
Detects potential cave entrances, sinkholes, and karst features from LiDAR elevation data using multiple scientific methods.
Depression Detection — Fill-and-diff algorithm finds closed depressions (sinkholes, pit entrances). Primary detection method.
Nested Depression — Level-set slicing finds sinkholes inside larger basins. Based on Wu (2016) algorithm.
TPI (Topographic Position Index) — Multi-scale elevation difference from surroundings at 5m, 15m, 30m radii.
Local Relief Model (LRM) — Subtracts smoothed surface to isolate small concave features. Based on Moyes et al. (2019).
Negative Openness — Mean nadir angle in 16 directions. High values indicate enclosed pits or shaft entrances.
Low Point Anomaly — LAS point cloud anomalies below the DEM surface (LAS/LAZ uploads only).
Multi-method consensus — Boosts candidates confirmed by 2+ detection methods.
Shape filtering — Penalises elongated features (ditches, roads). Boosts circular (sinkholes).
Depth-to-width ratio — Penalises very shallow, wide features.
Karst geology gating — Boosts candidates on known karst bedrock.
Slope context — Penalises candidates on flat terrain (likely ponds/fields).
Road/building proximity — Penalises candidates near mapped infrastructure.
Strict SVF/openness — Tighter thresholds for higher confidence.
DEM conditioning — Automatically breaches road/rail barriers before analysis to reduce false positives.
Sinking streams overlay — Shows where surface water disappears underground (swallets/ponors).
Karst geology overlay — BGR WHYMAP global karst map.
Known caves layer — Cave entrances and sinkholes from OpenStreetMap + Wikidata. Yellow = OSM caves, orange = OSM sinkholes, cyan = Wikidata caves.
AI review (optional) — Claude Vision analyses hillshade crops to filter false positives.
Multi-format export — CSV, GPX, KML, GeoJSON for use in GPS devices, Google Earth, QGIS.
Batch processing — Queue multiple areas for sequential analysis.
Change detection — Compare two DEMs to find new/deepened depressions.
RF classifier — Train a Random Forest on field-verified candidates to learn region-specific weights.
USGS 3DEP — 1m/3m/10m LiDAR bare-earth DEMs, USA, free, no key required.
Copernicus DEM — 30m global, free OpenTopography key.
ALOS AW3D30 — 30m global optical stereo, free OT key.
NASADEM — 30m global improved SRTM, free OT key.
SRTM GL3 — 90m global radar, free OT key.
File upload — GeoTIFF (.tif) or LAS/LAZ point clouds.
Moyes et al. (2019) — LRM for cave entrance detection. MDPI Geosciences 9(2):98
Wu (2016) — Level-set method for nested depression delineation. Geomorphology 266:92-107
Zhu et al. (2020) — ML sinkhole identification from LiDAR. J. Hydrology 588:125049
USGS (2020) — Automated GIS depression delineation on 1m LiDAR DEMs
How to use: Go to their Find Data map, click a dataset covering your area, draw a bounding box, and download as GeoTIFF. Then load it in Cave Finder via the Upload tab.
Note: Most high-res datasets now require an academic (.edu) email or a paid OT+ subscription for non-academics. The global DEMs (Copernicus, SRTM etc.) in the Setup tab still only need the free API key.