Porlock to Pittcombe Head°
4776.6 m · net rise 353.8 m · total ascent 368.2 m · overall 7.4% · confidence: needs confirmation · Hawk Combe · Somerset
Shape: stepped — 48% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 716 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 (51.2046, -3.6451)'). Corrections welcome.
needs review max5_over_45, max10_over_40 — treat short-window maxima here as provisional.
Gradient ladder what do windows mean?
| Window | Maximum | Located at | |
|---|---|---|---|
| 2 m (diagnostic) | ≈54% | 367–369 m | under overhead cover |
| 3 m (diagnostic) | ≈53% | 366–369 m | under overhead cover |
| 5 m | ≈51% | 364–369 m | under overhead cover |
| 10 m | ≈46% | 360–370 m | under overhead cover |
| 20 m | ≈36.4% | 351–371 m | under overhead cover terrain reads 37.3% at 350–370 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 25 m | ≈33.6% | 353–378 m | under overhead cover terrain reads 33.9% at 345–370 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 50 m | ≈26.0% | 351–401 m | under overhead cover terrain reads 27.0% at 345–395 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
| 100 m | ≈21.9% | 351–451 m | under overhead cover terrain reads 22.1% at 344–444 m across terrain that holds no road surface (dense canopy, no bench) — excluded |
may_start_earlier 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/SS8045.tif",
"data/cache/england/bulk_dtm_1m/SS8545.tif"
],
"calculated_at": "2026-08-15T05:18:12+00:00",
"road_source": "OpenStreetMap (local PBF extract)",
"road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
"osm_pbf_path": "data/cache/pbf/england-2026-08-12-roads.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": [
"SS8045.tif",
"SS8545.tif"
],
"climb_origin": "discovered",
"notes": "Coarse pass: max 12.4% over 200 m (Terrain 50), gain 117.2 m over 2890 m way. EXTENDED by graph walk: +10 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 3 overlapping proposal(s): porlock-hill, porlock-hill-2, porlock-hill-3",
"naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (51.2046, -3.6451)'"
}