Lane near Cellan°
2094.3 m · gain 123.9 m · overall 5.9% · Cellan · Sir Ceredigion - Ceredigion
Shape: stepped — 46% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 97 m.
An unlisted find of this survey, on no list we know of. It was discovered by analysing LiDAR terrain data and cross-checked against the OS road network, surface models and map tags — but despite all that, a discovery can still be an artifact of the terrain model or the map. Treat it as a well-evidenced hypothesis until someone has ridden it. If that someone is you, tell us what you found — photographs, corrections and local knowledge all welcome; the map links below let you scout it first.
° The name is provisional: this climb appears on no list we know of, so it was named from nearby map places. There is no evidence of local usage — (auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (52.1168, -4.0410)'). Corrections welcome.
≈ Overhead cover (tree canopy or structures) spans 55% of this route — detected by comparing the surface model (DSM, treetops and rooftops) against the terrain model (DTM, bare ground). Under cover the bare-ground model is built from fewer laser returns, so metre-scale readings can wobble; maxima whose window sits in a covered zone are marked ≈ below — less certain, not wrong. Longer windows average over more clean ground and are steadier.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | ≈54.0% | 1814–1816 m | under overhead cover terrain reads 88.0% at 1151–1153 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 3 m (diagnostic) | ≈51.2% | 1814–1817 m | under overhead cover terrain reads 64.1% at 1392–1395 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 5 m | ≈36.5% | 1812–1817 m | under overhead cover terrain reads 53.4% at 1519–1524 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 10 m | ≈33.2% | 1478–1488 m | under overhead cover terrain reads 48.7% at 1514–1524 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 20 m | ≈30.0% | 1469–1489 m | under overhead cover terrain reads 46.4% at 1504–1524 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 25 m | ≈30.1% | 1464–1489 m | under overhead cover terrain reads 46.1% at 1499–1524 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 50 m | ≈17.1% | 1947–1997 m | under overhead cover terrain reads 39.3% at 1483–1533 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 100 m | ≈15.5% | 1952–2052 m | under overhead cover terrain reads 28.5% at 1434–1534 m across a structure — excluded |
may_continue_beyond_end Extent detection suggests reviewing where this climb starts/ends.
Map
Check this route yourself: Google Maps route via their router · Street View at the base where coverage exists · geojson.io our exact measured line · OpenTopoMap
© OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap
Profile
Provenance
{
"analysis_version": "0.1.0",
"sample_interval_m": 1.0,
"interpolation": "bilinear",
"smoothing": "none",
"gradient_windows_m": [
5.0,
10.0,
20.0,
25.0,
50.0,
100.0
],
"diagnostic_windows_m": [
2.0,
3.0
],
"elevation_crs": "EPSG:27700",
"elevation_resolution_m": 1.0,
"elevation_tiles": [
"data/cache/wales/dtm_1m/wg_del_23_260248_20220117dtm.tif",
"data/cache/wales/dtm_1m/wg_del_30_260247_20220323dtm.tif"
],
"calculated_at": "2026-08-12T09:08:07+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/wales-2026-08-11.osm.pbf",
"osm_snapshot": "2026-08-10T20:21:40Z",
"elevation_provider": "Welsh Government",
"elevation_dataset": "Welsh Government LiDAR 1m DTM (2020-2023)",
"elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Crown copyright Welsh Government",
"elevation_catalogue_layer": "geonode:welsh_government_lidar_tile_catalogue_2020_2023",
"elevation_tile_ids": [
"wg_del_23_260248_20220117dtm.tif",
"wg_del_30_260247_20220323dtm.tif"
],
"elevation_capture_dates": [
"17-01-2022",
"23-03-2022"
],
"climb_origin": "discovered",
"notes": "Coarse pass: max 7.4% over 200 m (Terrain 50), gain 22.0 m over 1321 m way. EXTENDED by graph walk: +0 segment(s) at base, +2 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 2 overlapping proposal(s): discovered-lane-52-1110-4-0382, discovered-lane-52-1110-4-0469 ROAD-REVIEW: way 158652560: unnamed service way; way 158652560: service way, surface untagged ADOPTED (notable slice 2026-08-11): qualified-steep. AUTO-NAMED from gazetteer (hypothesis, unreviewed): was 'Discovered lane (52.1168, -4.0410)'.",
"naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (52.1168, -4.0410)'"
}