Port Quin to Trevan Point°
1138.9 m · net rise 70.8 m · total ascent 78.3 m · overall 6.2% · confidence: needs confirmation · Port Quin · Cornwall
Shape: stepped — 54% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 110 m.
Found purely from mapping and LiDAR data, and not yet matched against books, race records or lists — it may be well known to locals under a name we've never heard. It was cross-checked against the OS road network, surface models and map tags, but 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 you know this road, 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 is not yet matched to a documented name, 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 (50.5868, -4.8695)'). Corrections welcome.
needs review short_window_divergence — treat short-window maxima here as provisional.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | ≈47% | 20–22 m | under overhead cover terrain reads 89.7% at 15–17 m across a structure — excluded |
| 3 m (diagnostic) | ≈45% | 52–55 m | under overhead cover terrain reads 79.5% at 15–18 m across a structure — excluded |
| 5 m | ≈42% | 50–55 m | under overhead cover terrain reads 58.2% at 14–19 m across a structure — excluded |
| 10 m | ≈33% | 47–57 m | under overhead cover terrain reads 40.7% at 13–23 m across a structure — excluded |
| 20 m | ≈23.0% | 37–57 m | under overhead cover terrain reads 23.2% at 2–22 m across a structure — excluded |
| 25 m | 22.1% | 180–205 m | |
| 50 m | 20.4% | 155–205 m | |
| 100 m | 17.8% | 108–208 m |
may_start_earlierdescends_at_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
This climb's data: OCL JSON — the full gradient ladder, quality flags and provenance in the OpenClimb Ladder format.
Ridden it, or know better? Submit data for this climb no account needed
© 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/england/bulk_dtm_1m/SW9575.tif",
"data/cache/england/bulk_dtm_1m/SW9580.tif"
],
"calculated_at": "2026-08-19T18:14:42+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/england-2026-08-12.osm.pbf",
"osm_snapshot": "2026-08-12T20:21:46Z",
"elevation_provider": "Environment Agency",
"elevation_dataset": "EA LIDAR Composite DTM 1m (2022)",
"elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Environment Agency",
"elevation_coverage_id": "13787b9a-26a4-4775-8523-806d13af58fc__Lidar_Composite_Elevation_DTM_1m",
"elevation_tile_ids": [
"SW9575.tif",
"SW9580.tif"
],
"climb_origin": "discovered",
"notes": "Coarse pass: max 9.7% over 200 m (Terrain 50), gain 48.1 m over 974 m way. EXTENDED by graph walk: +1 segment(s) at base, +0 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): discovered-lane-50-5887-4-8676 ADOPTED (England launch slice 2026-08-16): clean-steep. AUTO-NAMED from gazetteer (hypothesis, unreviewed): was 'Discovered lane (50.5868, -4.8695)'.",
"naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (50.5868, -4.8695)'"
}