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Sunnini

2206.8 m · net rise 162.4 m · total ascent 174.4 m · overall 7.4% · evidence quality B (good) · Visperterminen · Valais/Wallis ·

Shape: sustained — 29% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 144 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 swisstopo’s swissTLM3D road model, OpenStreetMap and a second terrain model, 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.

Gradient ladder what do windows mean?

WindowMaximumLocated at
2 m (diagnostic)≈31%244–246 munder overhead cover terrain reads 63.5% at 29–31 m across a structure — excluded
3 m (diagnostic)≈29%244–247 munder overhead cover terrain reads 49.5% at 55–58 m across a structure — excluded
5 m≈23%1927–1932 munder overhead cover terrain reads 37.1% at 53–58 m across a structure — excluded
10 m≈18%72–82 munder overhead cover terrain reads 26.3% at 1–11 m across a structure — excluded
20 m≈16.0%67–87 munder overhead cover terrain reads 23.6% at 38–58 m across a structure — excluded
25 m≈14.9%243–268 munder overhead cover terrain reads 21.6% at 39–64 m across a structure — excluded
50 m≈12.8%244–294 munder overhead cover terrain reads 18.6% at 37–87 m across a structure — excluded
100 m≈12.5%2017–2117 munder overhead cover terrain reads 14.0% at 37–137 m across a structure — excluded

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.

Surface: paved (4% unpaved), according to swisstopo's swissTLM3D road model: unpaved for the first 70 m; paved from 70 m to the top. The steepest 25 m lies on the paved part.

Access: Listed 2026-09-11 (texture re-measure): with the step masked the steepest 25 m reads 14.9 %, below the ranking door — kept as a listed page.

Measured, not vetted. This page records what the laser record shows about the road's shape — nothing more. Nobody has necessarily ridden or inspected this road for the survey, and a page here is not a recommendation and no guarantee that the road is open, surfaced, rideable or safe. Gates, private sections, missing rights of way and hazards do not show up in elevation data. Check access and conditions on the ground and make your own judgment.

Ridden it, or know better? Submit data for this climb no account needed ·

Route colour = gradient over a 25 m window: <10% 10–20% 20–25% ≥25%

  © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap · aerial imagery © swisstopo

Sunnini LiDAR hillshade map with contours

Profile

The map, profile and gradient chart share one position — move your pointer over them and the marker follows. Colors are the gradient bands; the shaded span is the steepest 25 m. Any 25 m figure is good to about a point either way (why).

Sunnini elevation profile
Sunnini rolling gradient profile
 

Measurement card

Elevationswisstopo swissALTI3D — swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)
Resolution / CRS0.5 m grid, EPSG:2056; sampled every 1.0 m, bilinear interpolation
Tiles2634-1123, 2634-1124, 2634-1125, 2635-1123, 2635-1124, 2635-1125
Road centrelineOpenStreetMap (local PBF extract)
Quality statusevidence quality B; caveated windows: structure excluded, texture excluded
AnalysisOCL 0.1.0, analysis 0.1.0, run texture-ch-ch-260912, calculated 2026-09-12

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:2056",
  "elevation_resolution_m": 0.5,
  "elevation_tiles": [
    "data/cache/ch/swissalti3d_2024_2634-1123_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2024_2634-1124_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2024_2634-1125_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2024_2635-1123_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2024_2635-1124_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2024_2635-1125_0.5_2056_5728.tif"
  ],
  "calculated_at": "2026-09-12T01:32:53+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "output/texture-ch-ch/batch-switzerland-rchunk00.pbf",
  "osm_snapshot": "",
  "run_id": "texture-ch-ch-260912",
  "elevation_provider": "swisstopo swissALTI3D",
  "elevation_licence": "swisstopo open government data (OGD): free use, attribution '\u00a9 swisstopo' \u2014 https://www.swisstopo.admin.ch/en/terms-and-conditions",
  "elevation_dataset": "swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)",
  "elevation_tile_ids": [
    "2634-1123",
    "2634-1124",
    "2634-1125",
    "2635-1123",
    "2635-1124",
    "2635-1125"
  ],
  "climb_origin": "discovered",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}