Passing a 2D array as Pointer?

Question

I've following simple code #include using namespace std; typedef enum {wood , stone} material;

typedef struct{
  int x,y;
  bool isWall;
  material type;
}field;

#define n 16
#define m 12
int x=5;
int y=5;


void display( field **playground ){

  for (int j = 0; j < m; j++)
  {
    for (int i = 0; i < n; i++)
    {
       if (playground[i][j].isWall )
       {
          cout << "*";
       }
       else

          if (x == i && y == j){
             cout << "O";
          }
          else {
             cout << " ";
          }
    }
    cout << endl;
  }

}

int main(){


  field playground[n][m];
  for (int i=0; i<n; i++){
    for (int j=0; j<m; j++){
      playground[i][j].x=i;
      playground[i][j].y=j;
      playground[i][j].isWall=(i==0||i==(n-1)||(j==0&&i!=3) ||j==(m-1));
      if (playground[i][j].isWall && !(i==3 && j==0))
        playground [i][j].type=stone;
      else
        playground [i][j].type=wood;
    }
  }
  display(playground);

}

Why does this not work ? Do I understand it correct, that when you have a 2D array you need to pass consider it as a double pointer ?

Thanks