[
  {
    "type": "mapgen",
    "om_terrain": [ "ravine" ],
    "object": { "fill_ter": "t_open_air" }
  },
  {
    "type": "mapgen",
    "om_terrain": [ "ravine_floor" ],
    "object": { "fill_ter": "t_region_groundcover" }
  }
]
