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

Halswell Street

163.0 m · gain 20.7 m · overall 12.7% · Tyntetown · Rhondda Cynon Taf

Shape: sustained — 40% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 107 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)	22.8%	78–80 m
3 m (diagnostic)	22.0%	78–81 m
5 m	21.2%	78–83 m
10 m	21.2%	78–88 m
20 m	20.7%	78–98 m
25 m	20.7%	78–103 m
50 m	20.3%	72–122 m
100 m	18.9%	58–158 m

may_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

Halswell Street 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_5_306196_20201224dtm.tif"
  ],
  "calculated_at": "2026-08-12T09:10:32+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_5_306196_20201224dtm.tif"
  ],
  "elevation_capture_dates": [
    "24-12-2020"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 18.5% over 200 m (Terrain 50), gain 20.4 m over 110 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. ADOPTED (notable slice 2026-08-11): clean-steep."
}