diff --git a/blocks.py b/blocks.py
index 8016bbc..6eaa4ba 100644
--- a/blocks.py
+++ b/blocks.py
@@ -214,6 +214,10 @@ LEAVES = [
     'dark_oak_leaves',
 ]
 
+INDEXED = [
+    'chest',
+]
+
 
 NON_SOLID_IDS = set([SINGLE_SNOW])
 for block_name in NON_SOLID:
@@ -235,6 +239,11 @@ for block_name in LEAVES:
     for state in JSON_BLOCKS['minecraft:' + block_name]['states']:
         LEAF_IDS.add(state['id'])
 
+INDEXED_IDS = set()
+for block_name in INDEXED:
+    for state in JSON_BLOCKS['minecraft:' + block_name]['states']:
+        INDEXED_IDS.add(state['id'])
+
 
 def get(bid):
     name = BLOCKS[bid]
diff --git a/game.py b/game.py
index 162d60f..581c351 100644
--- a/game.py
+++ b/game.py
@@ -367,6 +367,9 @@ class Game:
             else:
                 reply = 'nothing open'
 
+        if command == 'loaded':
+            reply = str(self.g.chunks.get_loaded_area())
+
         if reply:
             print(reply)
             self.g.chat.send(reply)
diff --git a/protocol/managers.py b/protocol/managers.py
index 05da829..0224326 100644
--- a/protocol/managers.py
+++ b/protocol/managers.py
@@ -40,6 +40,7 @@ class ChunksManager:
         self.data = data_manager
         self.chunks = {}
         self.biomes = {}
+        self.index = {}
 
     def handle_block(self, block_packet):
         self.set_block_at(block_packet.location.x, block_packet.location.y, block_packet.location.z, block_packet.block_state_id)
@@ -53,7 +54,22 @@ class ChunksManager:
 
     def handle_chunk(self, chunk_packet):
         for i in chunk_packet.chunks:
-            self.chunks[(chunk_packet.x, i, chunk_packet.z)] = chunk_packet.chunks[i]        
+            chunk = chunk_packet.chunks[i]
+            self.chunks[(chunk_packet.x, i, chunk_packet.z)] = chunk
+
+            if chunk.sub_index:
+                dx = chunk.x * 16
+                dy = chunk.y * 16
+                dz = chunk.z * 16
+
+                for item_id, locations in chunk.sub_index.items():
+                    if item_id not in self.index:
+                        self.index[item_id] = []
+
+                    for l in locations:
+                        coords = (dx + l%16, dy + l//256, dz + l%256//16)
+                        self.index[item_id].append(coords)
+
         self.biomes[(chunk_packet.x, None, chunk_packet.z)] = chunk_packet.biomes # FIXME
 
     def register(self, connection):
diff --git a/protocol/packets.py b/protocol/packets.py
index 4bba2ca..5175c33 100644
--- a/protocol/packets.py
+++ b/protocol/packets.py
@@ -10,6 +10,8 @@ from minecraft.networking.types import (
 
 from protocol.types import Nbt, Slot, Entry
 
+import blocks
+
 
 class ChunkDataPacket(Packet):
     id = 0x20
@@ -75,6 +77,7 @@ class Chunk:
         self.z = z
         self.empty = empty
         self.entities = []
+        self.sub_index = {}
 
     def __repr__(self):
         return 'Chunk(%r, %r, %r)' % (self.x, self.y, self.z)
@@ -111,6 +114,11 @@ class Chunk:
                 n = self.palette[n]
             self.blocks.append(n)
 
+            if n in blocks.INDEXED_IDS:
+                if n not in self.sub_index:
+                    self.sub_index[n] = []
+                self.sub_index[n].append(i)
+
     def write_fields(self, packet_buffer):
         pass # TODO