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Llanberis Pass

1716.3 m · net rise 85.9 m · overall 5.0% · confidence: high · Bryant's Gully · Gwynedd

Shape: sustained — 32% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 37 m.

Matches: Wikipedia, Another 100 Greatest Cycling Climbs (Simon Warren) — Llanberis Pass — articles in English and Welsh; route-line 3 m from the pass point — No. 189, Llanberis Pass (official app, 2026 numbering).

Gradient ladder what do windows mean?

Window	Maximum	Located at
2 m (diagnostic)	13%	1252–1254 m
3 m (diagnostic)	13%	1252–1255 m
5 m	12%	1249–1254 m
10 m	12%	1247–1257 m
20 m	11.5%	1240–1260 m
25 m	11.3%	1240–1265 m
50 m	10.2%	1220–1270 m
100 m	8.2%	1178–1278 m

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

Llanberis Pass 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_11_261356_20210302dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_11_261357_20210302dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_11_262356_20210302dtm.tif",
    "data/cache/wales/dtm_1m/wg_del_11_262357_20210302dtm.tif"
  ],
  "calculated_at": "2026-08-12T02:15:23+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_11_261356_20210302dtm.tif",
    "wg_del_11_261357_20210302dtm.tif",
    "wg_del_11_262356_20210302dtm.tif",
    "wg_del_11_262357_20210302dtm.tif"
  ],
  "elevation_capture_dates": [
    "02-03-2021"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 9.3% over 200 m (Terrain 50), gain 42.0 m over 829 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. DEDUPE: absorbed 1 overlapping proposal(s): discovered-lane-53-0943-4-0634",
  "renamed": "2026-08-13: RENAMED per identification-certain policy: route-line 3 m from the Wikidata pass point; en+cy Wikipedia articles"
}