{
  "name": "Alto de Letras",
  "slug": "alto-de-letras",
  "url": "https://www.bestdrivingroads.com/roads/alto-de-letras/",
  "summary": "One of the longest continuously paved road climbs on earth: 81 km rising from Mariquita at 468 m to the 3,692 m páramo pass before descending into Manizales, through five distinct ecosystems.",
  "roadNumbers": [
    "RN50"
  ],
  "location": {
    "country": "Colombia",
    "region": "Tolima / Caldas",
    "start": {
      "name": "Mariquita",
      "lat": 5.199349,
      "lon": -74.892433
    },
    "end": {
      "name": "Manizales",
      "lat": 5.056968,
      "lon": -75.516487
    }
  },
  "measurements": {
    "lengthMiles": 71.9,
    "lengthKm": 115.7,
    "driveMinutes": 167,
    "corners": 491,
    "hairpins": 12,
    "maxGradientPercent": 14,
    "summitMetres": 3688,
    "elevationConfidence": "measured",
    "difficulty": "demanding",
    "tightnessOutOf10": 8
  },
  "timing": {
    "bestSeasons": [
      "summer",
      "winter"
    ]
  },
  "conditions": {},
  "hazards": [
    "Extreme altitude gain",
    "Altitude sickness",
    "Heavy truck traffic",
    "Potholed sections",
    "Rapidly changing weather near the summit"
  ],
  "scenery": [
    "mountain",
    "valley",
    "forest"
  ],
  "pointsOfInterest": [
    "El Alto",
    "Páramo de Letras",
    "Cerro Bravo"
  ],
  "geometry": {
    "pointCount": 1005
  },
  "attribution": {
    "source": "Routes - bestdrivingroads.com",
    "citation": "Cite with a link to the road page. Stats are measured from the mapped line, not copied from other lists; where elevationConfidence is \"approximate\" the 30 m DEM cannot resolve that line and the elevation figures are indicative.",
    "roadGeometry": "(c) OpenStreetMap contributors, ODbL",
    "terms": "Facts are free to cite with attribution; bulk reproduction of the catalogue requires permission (simon@keane.studio)."
  },
  "updated": "2026-08-03"
}