Something

using UnityEngine;
using System.Collections;

public class CubeArray : MonoBehaviour {

	public GameObject[,,] Cubes;
	
	// Use this for initialization
	void Start ()
	{
		Cubes[0,0,0]= Instantiate(Block, Vector3 (0, 0, 0), Quaternion.identity);
	}
	
	// Update is called once per frame
	void Update () {
	
	}
}