diff --git a/ClassicalSharp/ClassicalSharp.csproj b/ClassicalSharp/ClassicalSharp.csproj
index a3c2e5202..32003468b 100644
--- a/ClassicalSharp/ClassicalSharp.csproj
+++ b/ClassicalSharp/ClassicalSharp.csproj
@@ -124,6 +124,7 @@
     <Compile Include="Map\ChunkMeshBuilderTex2Col4.cs" />
     <Compile Include="Map\IMapFile.cs" />
     <Compile Include="Map\Map.cs" />
+    <Compile Include="Map\MapCw.cs" />
     <Compile Include="Map\MapDat.cs" />
     <Compile Include="Map\MapFcm3.cs" />
     <Compile Include="Model\BlockModel.cs" />
diff --git a/ClassicalSharp/Map/MapCw.cs b/ClassicalSharp/Map/MapCw.cs
new file mode 100644
index 000000000..205e0833d
--- /dev/null
+++ b/ClassicalSharp/Map/MapCw.cs
@@ -0,0 +1,127 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using System.Text;
+using System.Net;
+
+namespace ClassicalSharp {
+
+	public sealed class MapCw : IMapFile {
+		
+		public override bool SupportsLoading {
+			get { return true; }
+		}
+		
+		public override bool SupportsSaving {
+			get { return true; }
+		}
+
+		BinaryReader reader;
+		NbtTag invalid = default( NbtTag );
+		public override byte[] Load( Stream stream, Game game, out int width, out int height, out int length ) {
+			using( GZipStream wrapper = new GZipStream( stream, CompressionMode.Decompress ) ) {
+				reader = new BinaryReader( wrapper );
+				if( reader.ReadByte() != (byte)NbtTagType.Compound )
+					throw new InvalidDataException( "Nbt file must start with Tag_Compound" );
+				
+				invalid.TagId = NbtTagType.Invalid;
+				NbtTag root = ReadTag( (byte)NbtTagType.Compound, true );
+			}
+			length = width = height = 0;
+			return null;
+		}
+		
+		unsafe NbtTag ReadTag( byte typeId, bool readTagName ) {
+			if( typeId == 0 ) return invalid;
+			
+			NbtTag tag = default( NbtTag );
+			tag.Name = readTagName ? ReadString() : null;
+			tag.TagId = (NbtTagType)typeId;
+			
+			switch( (NbtTagType)typeId ) {
+				case NbtTagType.Int8:
+					tag.Value = reader.ReadByte(); break;
+				case NbtTagType.Int16:
+					tag.Value = ReadInt16(); break;
+				case NbtTagType.Int32:
+					tag.Value = ReadInt32(); break;
+				case NbtTagType.Int64:
+					tag.Value = ReadInt64(); break;
+				case NbtTagType.Real32:
+					int temp32 = ReadInt32();
+					tag.Value = *(float*)&temp32; break;
+				case NbtTagType.Real64:
+					long temp64 = ReadInt64();
+					tag.Value = *(double*)&temp64; break;
+				case NbtTagType.Int8Array:
+					tag.Value = reader.ReadBytes( ReadInt32() ); break;
+				case NbtTagType.String:
+					tag.Value = ReadString(); break;
+					
+				case NbtTagType.List:
+					NbtList list = new NbtList();
+					list.ChildTagId = (NbtTagType)reader.ReadByte();
+					list.ChildrenValues = new object[ReadInt32()];
+					for( int i = 0; i < list.ChildrenValues.Length; i++ ) {
+						list.ChildrenValues[i] = ReadTag( (byte)list.ChildTagId, false );
+					}
+					tag.Value = list; break;
+					
+				case NbtTagType.Compound:
+					Dictionary<string, NbtTag> children = new Dictionary<string, NbtTag>();
+					NbtTag child;
+					while( (child = ReadTag( reader.ReadByte(), true )).TagId != NbtTagType.Invalid ) {
+						children[child.Name] = child;
+					}
+					tag.Value = children; break;
+					
+				case NbtTagType.Int32Array:
+					int[] array = new int[ReadInt32()];
+					for( int i = 0; i < array.Length; i++ )
+						array[i] = ReadInt32();
+					tag.Value = array; break;
+					
+				default:
+					throw new InvalidDataException( "Unrecognised tag id: " + typeId );
+			}
+			return tag;
+		}
+		
+		struct NbtTag {
+			public string Name;
+			public object Value;
+			public NbtTagType TagId;
+		}
+		
+		class NbtList {
+			public NbtTagType ChildTagId;
+			public object[] ChildrenValues;
+		}
+		
+		
+		enum NbtTagType : byte {
+			End = 0,
+			Int8 = 1,
+			Int16 = 2,
+			Int32 = 3,
+			Int64 = 4,
+			Real32 = 5,
+			Real64 = 6,
+			Int8Array = 7,
+			String = 8,
+			List = 9,
+			Compound = 10,
+			Int32Array = 11,
+			Invalid = 255,
+		}
+		
+		long ReadInt64() { return IPAddress.HostToNetworkOrder( reader.ReadInt64() ); }
+		int ReadInt32() { return IPAddress.HostToNetworkOrder( reader.ReadInt32() ); }
+		short ReadInt16() { return IPAddress.HostToNetworkOrder( reader.ReadInt16() ); }
+		string ReadString() { return Encoding.UTF8.GetString( reader.ReadBytes( (ushort)ReadInt16() ) ); }
+
+		public override void Save( Stream stream, Game game ) {
+		}
+	}
+}
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