from fastapi import APIRouter, HTTPException

towns = [
    {"name": "Yaoundé", "region": "Centre"},
    {"name": "Douala", "region": "Littoral"},
    {"name": "Garoua", "region": "Nord"},
    {"name": "Bafoussam", "region": "Ouest"},
    {"name": "Bamenda", "region": "Nord-Ouest"},
    {"name": "Ngaoundéré", "region": "Adamaoua"},
    {"name": "Maroua", "region": "Extrême-Nord"},
    {"name": "Bertoua", "region": "Est"},
    {"name": "Ebolowa", "region": "Sud"},
    {"name": "Buea", "region": "Sud-Ouest"}
]

router = APIRouter()

@router.post("/open")
async def get_towns():
    """Returns list of towns in Cameroon"""
    if not towns:
        raise HTTPException(status_code=404, detail="No towns found")

    return {
        "method": "POST",
        "_verb": "post",
        "data": towns
    }
```

This code defines a list of towns in Cameroon with their respective regions. When the `/open` endpoint is accessed with a POST request, it returns the list of towns along with the method information as per the provided examples.