BETA — measurements and names under active refinement. Seen a sign, a gate, or a better name? Report it (photos welcome).

Heol y Banc

1670.3 m · gain 164.2 m · overall 9.8% · Llygadywawr · Sir Gaerfyrddin - Carmarthenshire

Shape: sustained — 39% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 295 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.

Gradient ladder what do windows mean?

Window	Maximum	Located at
2 m (diagnostic)	23.5%	19–21 m
3 m (diagnostic)	23.3%	19–22 m
5 m	22.9%	26–31 m
10 m	22.5%	24–34 m
20 m	22.1%	14–34 m
25 m	21.9%	15–40 m
50 m	19.2%	112–162 m
100 m	17.5%	64–164 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

Heol y Banc LiDAR hillshade map with contours

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_21_248211_20220113dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_21_248212_20220113dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_21_249211_20220113dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_21_249212_20220113dtm.tif"
  ],
  "calculated_at": "2026-08-12T09:10:38+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_21_248211_20220113dtm.tif",
    "wg_del_21_248212_20220113dtm.tif",
    "wg_del_21_249211_20220113dtm.tif",
    "wg_del_21_249212_20220113dtm.tif"
  ],
  "elevation_capture_dates": [
    "13-01-2022"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 11.9% over 200 m (Terrain 50), gain 93.6 m over 1098 m way. EXTENDED by graph walk: +8 segment(s) at base, +1 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): ffordd-aneurin-2 ADOPTED (notable slice 2026-08-11): clean-steep."
}