Porthoustock to St Keverne°
1588.2 m · net rise 81.1 m · total ascent 94.0 m · overall 5.1% · confidence: high · Trenance · Cornwall
Shape: sustained — 44% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 182 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 (50.0521, -5.0769)'). Corrections welcome.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | 42% | 1578–1580 m | |
| 3 m (diagnostic) | 39% | 1578–1581 m | |
| 5 m | 29% | 1577–1582 m | |
| 10 m | 22% | 72–82 m | |
| 20 m | 21.1% | 88–108 m | |
| 25 m | 20.4% | 88–113 m | |
| 50 m | 19.3% | 59–109 m | |
| 100 m | 18.2% | 24–124 m |
may_start_earliermay_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
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/SW7520.tif",
"data/cache/england/bulk_dtm_1m/SW8020.tif"
],
"calculated_at": "2026-08-19T22:11:47+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": [
"SW7520.tif",
"SW8020.tif"
],
"climb_origin": "discovered",
"notes": "Coarse pass: max 9.1% over 200 m (Terrain 50), gain 47.4 m over 1336 m way. EXTENDED by graph walk: +1 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 1 overlapping proposal(s): discovered-lane-50-0554-5-0670 ADOPTED (England launch slice 2026-08-16): clean-steep. AUTO-NAMED from gazetteer (hypothesis, unreviewed): was 'Discovered lane (50.0521, -5.0769)'.",
"naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (50.0521, -5.0769)'"
}