c++ - 列挙型が宣言されていません

Question

次のヘッダーを使用しますNode.h。

/*
    INCLUDE PROTECTION
*/
#ifndef NODE_H_INCLUDED
#define NODE_H_INCLUDED

/*
    Include
*/
#include <vector>
#include <unordered_map>
//#include "NodeConnection.h"
#include "Tile.h"
#include "Network.h"

/*
    Declarations
*/
class Network;
class NodeConnection;

class Node {
    private:

        Tile* tile;

        std :: vector <NodeConnection*> connections;
        std :: unordered_map <Node*, NodeConnection*> connectionmap;

    public:

        /* Enumeration */

        enum NAVIGATION {
            RIGHT = 0, 
            UP = 1, 
            LEFT = 2, 
            DOWN = 3
        };

        Node (Tile* _tile);

        void FindNeighbours(Board* board, Network* network);

        void SetNodeConnection(Node* node, NodeConnection* nodeconnection);

};

struct TileNavigation {
    Tile* tile;
    enum Node :: NAVIGATION navigation;
};

#endif

のヘッダーには次のように記述しNodeConnection.hます。

/*
    INCLUDE PROTECTION
*/
#ifndef NODECONNECTION_H_INCLUDED
#define NODECONNECTION_H_INCLUDED

/*
    Include
*/
#include <string>
#include "Node.h"

/*
    Declarations
*/
class Node;
struct Nodes;


enum ConnectionType {
    WALLCONN, PATHCONN, UNKNOWN
};

class NodeConnection {
    private:

        enum ConnectionType contype;

        struct Nodes;

    public:

        //NodeConnection ();
        NodeConnection (Node* a, Node* b,  NAVIGATION initial_nav);
};

struct Nodes {

    Node* left;
    Node* right;
    std :: string steps;

};

#endif

Node :: NAVIGATIONとを試しNAVIGATIONましたが、それでもそれは私に言い続けます

"   'NAVIGATION' has not been declared   "

私が間違っていることを誰かが知っていますか？ポインタを前もってありがとう。