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Lane near Cwm°

2426.3 m · net rise 121.9 m · total ascent 137.2 m · overall 5.0% · confidence: good · Cwm · Powys

Shape: sustained — 38% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 116 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 (52.5017, -3.0856)'). Corrections welcome.

Gradient ladder what do windows mean?

WindowMaximumLocated at
2 m (diagnostic)≈40%14–16 munder overhead cover
3 m (diagnostic)≈36%14–17 munder overhead cover
5 m≈29%12–17 munder overhead cover
10 m≈23%7–17 munder overhead cover
20 m20.8%9–29 m
25 m20.6%4–29 m
50 m18.5%5–55 m
100 m16.3%0–100 m

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

Lane near Cwm LiDAR hillshade map with contours

Profile

Lane near Cwm elevation profile Lane near Cwm rolling gradient 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/SO2585.tif",
    "data/cache/england/bulk_dtm_1m/SO2590.tif"
  ],
  "calculated_at": "2026-08-19T18:27:20+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": [
    "SO2585.tif",
    "SO2590.tif"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 10.1% over 200 m (Terrain 50), gain 94.1 m over 1369 m way. EXTENDED by graph walk: +0 segment(s) at base, +1 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. ADOPTED (England launch slice 2026-08-16): clean-steep. AUTO-NAMED from gazetteer (hypothesis, unreviewed): was 'Discovered lane (52.5017, -3.0856)'.",
  "naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (52.5017, -3.0856)'"
}