diff --git a/src/mudlib/commands/containers.py b/src/mudlib/commands/containers.py
new file mode 100644
index 0000000..fa31459
--- /dev/null
+++ b/src/mudlib/commands/containers.py
@@ -0,0 +1,94 @@
+"""Open and close commands for containers."""
+
+from mudlib.commands import CommandDefinition, register
+from mudlib.container import Container
+from mudlib.player import Player
+from mudlib.thing import Thing
+from mudlib.zone import Zone
+
+
+def _find_container(name: str, player: Player) -> Container | Thing | None:
+    """Find a thing by name in inventory first, then on ground.
+
+    Returns Thing if found (caller must check if it's a Container).
+    Returns None if not found.
+    """
+    name_lower = name.lower()
+
+    # Check inventory first
+    for obj in player.contents:
+        if not isinstance(obj, Thing):
+            continue
+        if obj.name.lower() == name_lower:
+            return obj
+        if name_lower in (a.lower() for a in obj.aliases):
+            return obj
+
+    # Check ground at player's position
+    zone = player.location
+    if zone is None or not isinstance(zone, Zone):
+        return None
+
+    for obj in zone.contents_at(player.x, player.y):
+        if not isinstance(obj, Thing):
+            continue
+        if obj.name.lower() == name_lower:
+            return obj
+        if name_lower in (a.lower() for a in obj.aliases):
+            return obj
+
+    return None
+
+
+async def cmd_open(player: Player, args: str) -> None:
+    """Open a container."""
+    if not args.strip():
+        await player.send("Open what?\r\n")
+        return
+
+    thing = _find_container(args.strip(), player)
+    if thing is None:
+        await player.send("You don't see that here.\r\n")
+        return
+
+    if not isinstance(thing, Container):
+        await player.send("You can't open that.\r\n")
+        return
+
+    if not thing.closed:
+        await player.send("It's already open.\r\n")
+        return
+
+    if thing.locked:
+        await player.send("It's locked.\r\n")
+        return
+
+    thing.closed = False
+    await player.send(f"You open the {thing.name}.\r\n")
+
+
+async def cmd_close(player: Player, args: str) -> None:
+    """Close a container."""
+    if not args.strip():
+        await player.send("Close what?\r\n")
+        return
+
+    thing = _find_container(args.strip(), player)
+    if thing is None:
+        await player.send("You don't see that here.\r\n")
+        return
+
+    if not isinstance(thing, Container):
+        await player.send("You can't close that.\r\n")
+        return
+
+    if thing.closed:
+        await player.send("It's already closed.\r\n")
+        return
+
+    thing.closed = True
+    await player.send(f"You close the {thing.name}.\r\n")
+
+
+register(CommandDefinition("open", cmd_open))
+register(CommandDefinition("close", cmd_close))
diff --git a/src/mudlib/server.py b/src/mudlib/server.py
index 55c758c..2e1483b 100644
--- a/src/mudlib/server.py
+++ b/src/mudlib/server.py
@@ -31,8 +31,6 @@ from mudlib.effects import clear_expired
 from mudlib.if_session import broadcast_to_spectators
 from mudlib.mob_ai import process_mobs
 from mudlib.mobs import load_mob_templates, mob_templates
-from mudlib.thing import Thing
-from mudlib.things import load_thing_templates, spawn_thing, thing_templates
 from mudlib.player import Player, players
 from mudlib.resting import process_resting
 from mudlib.store import (
diff --git a/src/mudlib/zones.py b/src/mudlib/zones.py
new file mode 100644
index 0000000..f578105
--- /dev/null
+++ b/src/mudlib/zones.py
@@ -0,0 +1,30 @@
+"""Zone registry and loading."""
+
+from __future__ import annotations
+
+from mudlib.zone import Zone
+
+# Module-level zone registry
+zone_registry: dict[str, Zone] = {}
+
+
+def register_zone(name: str, zone: Zone) -> None:
+    """Register a zone by name.
+
+    Args:
+        name: Unique name for the zone
+        zone: Zone instance to register
+    """
+    zone_registry[name] = zone
+
+
+def get_zone(name: str) -> Zone | None:
+    """Look up a zone by name.
+
+    Args:
+        name: Zone name to look up
+
+    Returns:
+        Zone instance if found, None otherwise
+    """
+    return zone_registry.get(name)
diff --git a/tests/test_container_display.py b/tests/test_container_display.py
new file mode 100644
index 0000000..6ff9050
--- /dev/null
+++ b/tests/test_container_display.py
@@ -0,0 +1,152 @@
+"""Tests for container state display in look and inventory commands."""
+
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from mudlib.container import Container
+from mudlib.player import Player
+from mudlib.thing import Thing
+from mudlib.zone import Zone
+
+
+@pytest.fixture
+def mock_writer():
+    writer = MagicMock()
+    writer.write = MagicMock()
+    writer.drain = AsyncMock()
+    return writer
+
+
+@pytest.fixture
+def mock_reader():
+    return MagicMock()
+
+
+@pytest.fixture
+def test_zone():
+    terrain = [["." for _ in range(10)] for _ in range(10)]
+    return Zone(
+        name="testzone",
+        width=10,
+        height=10,
+        toroidal=True,
+        terrain=terrain,
+    )
+
+
+@pytest.fixture
+def player(mock_reader, mock_writer, test_zone):
+    p = Player(
+        name="TestPlayer",
+        x=5,
+        y=5,
+        reader=mock_reader,
+        writer=mock_writer,
+        location=test_zone,
+    )
+    return p
+
+
+# --- look command container display ---
+
+
+@pytest.mark.asyncio
+async def test_look_shows_closed_container(player, test_zone, mock_writer):
+    """look shows closed containers with (closed) suffix."""
+    from mudlib.commands.look import cmd_look
+
+    Container(name="chest", location=test_zone, x=5, y=5, closed=True)
+    await cmd_look(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "chest (closed)" in output
+
+
+@pytest.mark.asyncio
+async def test_look_shows_open_empty_container(player, test_zone, mock_writer):
+    """look shows open empty containers with (open, empty) suffix."""
+    from mudlib.commands.look import cmd_look
+
+    Container(name="chest", location=test_zone, x=5, y=5, closed=False)
+    await cmd_look(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "chest (open, empty)" in output
+
+
+@pytest.mark.asyncio
+async def test_look_shows_open_container_with_contents(
+    player, test_zone, mock_writer
+):
+    """look shows open containers with their contents."""
+    from mudlib.commands.look import cmd_look
+
+    chest = Container(name="chest", location=test_zone, x=5, y=5, closed=False)
+    Thing(name="rock", location=chest)
+    Thing(name="coin", location=chest)
+    await cmd_look(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "chest (open, containing: rock, coin)" in output
+
+
+@pytest.mark.asyncio
+async def test_look_shows_regular_things_unchanged(player, test_zone, mock_writer):
+    """look shows regular Things without container suffixes."""
+    from mudlib.commands.look import cmd_look
+
+    Thing(name="rock", location=test_zone, x=5, y=5)
+    await cmd_look(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "On the ground: rock" in output
+    assert "(closed)" not in output
+    assert "(open" not in output
+
+
+# --- inventory command container display ---
+
+
+@pytest.mark.asyncio
+async def test_inventory_shows_closed_container(player, mock_writer):
+    """inventory shows closed containers with (closed) suffix."""
+    from mudlib.commands.things import cmd_inventory
+
+    Container(name="sack", location=player, closed=True)
+    await cmd_inventory(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "sack (closed)" in output
+
+
+@pytest.mark.asyncio
+async def test_inventory_shows_open_empty_container(player, mock_writer):
+    """inventory shows open empty containers with (open, empty) suffix."""
+    from mudlib.commands.things import cmd_inventory
+
+    Container(name="sack", location=player, closed=False)
+    await cmd_inventory(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "sack (open, empty)" in output
+
+
+@pytest.mark.asyncio
+async def test_inventory_shows_container_with_contents(player, mock_writer):
+    """inventory shows open containers with their contents."""
+    from mudlib.commands.things import cmd_inventory
+
+    sack = Container(name="sack", location=player, closed=False)
+    Thing(name="rock", location=sack)
+    Thing(name="gem", location=sack)
+    await cmd_inventory(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "sack (open, containing: rock, gem)" in output
+
+
+@pytest.mark.asyncio
+async def test_inventory_shows_regular_things_unchanged(player, mock_writer):
+    """inventory shows regular Things without container suffixes."""
+    from mudlib.commands.things import cmd_inventory
+
+    Thing(name="rock", location=player)
+    await cmd_inventory(player, "")
+    output = "".join(call[0][0] for call in mock_writer.write.call_args_list)
+    assert "  rock\r\n" in output
+    assert "(closed)" not in output
+    assert "(open" not in output
diff --git a/tests/test_open_close.py b/tests/test_open_close.py
new file mode 100644
index 0000000..8fc3457
--- /dev/null
+++ b/tests/test_open_close.py
@@ -0,0 +1,226 @@
+"""Tests for open and close commands."""
+
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from mudlib.commands import _registry
+from mudlib.container import Container
+from mudlib.player import Player
+from mudlib.thing import Thing
+from mudlib.zone import Zone
+
+
+@pytest.fixture
+def mock_writer():
+    writer = MagicMock()
+    writer.write = MagicMock()
+    writer.drain = AsyncMock()
+    return writer
+
+
+@pytest.fixture
+def mock_reader():
+    return MagicMock()
+
+
+@pytest.fixture
+def test_zone():
+    terrain = [["." for _ in range(10)] for _ in range(10)]
+    return Zone(
+        name="testzone",
+        width=10,
+        height=10,
+        toroidal=True,
+        terrain=terrain,
+    )
+
+
+@pytest.fixture
+def player(mock_reader, mock_writer, test_zone):
+    p = Player(
+        name="TestPlayer",
+        x=5,
+        y=5,
+        reader=mock_reader,
+        writer=mock_writer,
+        location=test_zone,
+    )
+    return p
+
+
+# --- cmd_open ---
+
+
+@pytest.mark.asyncio
+async def test_open_container_on_ground(player, test_zone, mock_writer):
+    """open finds container on ground and sets closed=False."""
+    from mudlib.commands.containers import cmd_open
+
+    chest = Container(name="chest", location=test_zone, x=5, y=5, closed=True)
+    await cmd_open(player, "chest")
+    assert chest.closed is False
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "open" in output.lower() and "chest" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_open_container_in_inventory(player, test_zone, mock_writer):
+    """open finds container in player inventory and sets closed=False."""
+    from mudlib.commands.containers import cmd_open
+
+    box = Container(name="box", location=player, closed=True)
+    await cmd_open(player, "box")
+    assert box.closed is False
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "open" in output.lower() and "box" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_open_no_args(player, mock_writer):
+    """open with no arguments gives usage hint."""
+    from mudlib.commands.containers import cmd_open
+
+    await cmd_open(player, "")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "open what" in output.lower() or "what" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_open_already_open(player, test_zone, mock_writer):
+    """open on already-open container gives feedback."""
+    from mudlib.commands.containers import cmd_open
+
+    chest = Container(name="chest", location=test_zone, x=5, y=5, closed=False)
+    await cmd_open(player, "chest")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "already open" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_open_locked_container(player, test_zone, mock_writer):
+    """open on locked container gives feedback."""
+    from mudlib.commands.containers import cmd_open
+
+    chest = Container(
+        name="chest", location=test_zone, x=5, y=5, closed=True, locked=True
+    )
+    await cmd_open(player, "chest")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "locked" in output.lower()
+    # Container should still be closed
+    assert chest.closed is True
+
+
+@pytest.mark.asyncio
+async def test_open_not_found(player, test_zone, mock_writer):
+    """open on non-existent thing gives feedback."""
+    from mudlib.commands.containers import cmd_open
+
+    await cmd_open(player, "chest")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "don't see" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_open_matches_aliases(player, test_zone):
+    """open matches container aliases."""
+    from mudlib.commands.containers import cmd_open
+
+    chest = Container(
+        name="wooden chest",
+        aliases=["chest", "box"],
+        location=test_zone,
+        x=5,
+        y=5,
+        closed=True,
+    )
+    await cmd_open(player, "box")
+    assert chest.closed is False
+
+
+@pytest.mark.asyncio
+async def test_open_non_container(player, test_zone, mock_writer):
+    """open on non-container thing gives feedback."""
+    from mudlib.commands.containers import cmd_open
+
+    rock = Thing(name="rock", location=test_zone, x=5, y=5)
+    await cmd_open(player, "rock")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "can't open" in output.lower()
+
+
+# --- cmd_close ---
+
+
+@pytest.mark.asyncio
+async def test_close_container_on_ground(player, test_zone, mock_writer):
+    """close finds container on ground and sets closed=True."""
+    from mudlib.commands.containers import cmd_close
+
+    chest = Container(name="chest", location=test_zone, x=5, y=5, closed=False)
+    await cmd_close(player, "chest")
+    assert chest.closed is True
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "close" in output.lower() and "chest" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_close_container_in_inventory(player, test_zone, mock_writer):
+    """close finds container in inventory and sets closed=True."""
+    from mudlib.commands.containers import cmd_close
+
+    box = Container(name="box", location=player, closed=False)
+    await cmd_close(player, "box")
+    assert box.closed is True
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "close" in output.lower() and "box" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_close_already_closed(player, test_zone, mock_writer):
+    """close on already-closed container gives feedback."""
+    from mudlib.commands.containers import cmd_close
+
+    chest = Container(name="chest", location=test_zone, x=5, y=5, closed=True)
+    await cmd_close(player, "chest")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "already closed" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_close_no_args(player, mock_writer):
+    """close with no arguments gives usage hint."""
+    from mudlib.commands.containers import cmd_close
+
+    await cmd_close(player, "")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "close what" in output.lower() or "what" in output.lower()
+
+
+@pytest.mark.asyncio
+async def test_close_non_container(player, test_zone, mock_writer):
+    """close on non-container thing gives feedback."""
+    from mudlib.commands.containers import cmd_close
+
+    rock = Thing(name="rock", location=test_zone, x=5, y=5)
+    await cmd_close(player, "rock")
+    output = mock_writer.write.call_args_list[-1][0][0]
+    assert "can't close" in output.lower()
+
+
+# --- command registration ---
+
+
+def test_open_command_registered():
+    """open command is registered."""
+    import mudlib.commands.containers  # noqa: F401
+
+    assert "open" in _registry
+
+
+def test_close_command_registered():
+    """close command is registered."""
+    import mudlib.commands.containers  # noqa: F401
+
+    assert "close" in _registry
diff --git a/tests/test_zone_registry.py b/tests/test_zone_registry.py
new file mode 100644
index 0000000..d61ae56
--- /dev/null
+++ b/tests/test_zone_registry.py
@@ -0,0 +1,62 @@
+"""Tests for zone registry."""
+
+import pytest
+
+from mudlib.zone import Zone
+from mudlib.zones import get_zone, register_zone, zone_registry
+
+
+@pytest.fixture(autouse=True)
+def clear_registry():
+    """Clear zone registry before each test."""
+    zone_registry.clear()
+    yield
+    zone_registry.clear()
+
+
+def test_register_zone():
+    """Register a zone by name."""
+    zone = Zone(name="test_zone", width=10, height=10, terrain=[], toroidal=False)
+    register_zone("test_zone", zone)
+
+    assert "test_zone" in zone_registry
+    assert zone_registry["test_zone"] is zone
+
+
+def test_get_zone():
+    """Look up a zone by name."""
+    zone = Zone(name="test_zone", width=10, height=10, terrain=[], toroidal=False)
+    register_zone("test_zone", zone)
+
+    retrieved = get_zone("test_zone")
+    assert retrieved is zone
+
+
+def test_get_zone_unknown():
+    """Get None for unknown zone name."""
+    result = get_zone("nonexistent")
+    assert result is None
+
+
+def test_register_multiple_zones():
+    """Register multiple zones."""
+    zone1 = Zone(name="zone1", width=10, height=10, terrain=[], toroidal=False)
+    zone2 = Zone(name="zone2", width=20, height=15, terrain=[], toroidal=True)
+
+    register_zone("zone1", zone1)
+    register_zone("zone2", zone2)
+
+    assert len(zone_registry) == 2
+    assert get_zone("zone1") is zone1
+    assert get_zone("zone2") is zone2
+
+
+def test_overwrite_zone():
+    """Registering same name twice overwrites."""
+    zone1 = Zone(name="zone", width=10, height=10, terrain=[], toroidal=False)
+    zone2 = Zone(name="zone", width=20, height=20, terrain=[], toroidal=False)
+
+    register_zone("zone", zone1)
+    register_zone("zone", zone2)
+
+    assert get_zone("zone") is zone2