diff --git a/ca.py b/ca.py
index 3d2ff6e..8035e53 100644
--- a/ca.py
+++ b/ca.py
@@ -26,7 +26,7 @@ def main(argv):
 
     log.init()
 
-    bounds = Rect(Point(), Size(20, 20))
+    bounds = Rect(Point(), Size(60, 20))
 
     config = CellularAtomataMapGenerator.Configuration()
     config.number_of_rounds = args.rounds
diff --git a/erynrl/map/generator/cellular_atomata.py b/erynrl/map/generator/cellular_atomata.py
index c1e2f0b..1fad789 100644
--- a/erynrl/map/generator/cellular_atomata.py
+++ b/erynrl/map/generator/cellular_atomata.py
@@ -2,14 +2,16 @@
 
 import random
 from dataclasses import dataclass
-from typing import Optional
+from typing import Optional, TYPE_CHECKING
 
 import numpy as np
 
 from ... import log
-from ...geometry import Point, Rect
-from ..grid import make_grid
-from ..tile import Floor, Wall
+from ...geometry import Point, Rect, Vector
+from ..tile import Empty, Floor, Wall, tile_datatype
+
+if TYPE_CHECKING:
+    from .. import Map
 
 
 class CellularAtomataMapGenerator:
@@ -38,6 +40,7 @@ class CellularAtomataMapGenerator:
         Initializer
 
         ### Parameters
+
         `bounds` : `Rect`
             A rectangle representing the bounds of the cellular atomaton
         `config` : `Optional[Configuration]`
@@ -46,7 +49,7 @@ class CellularAtomataMapGenerator:
         '''
         self.bounds = bounds
         self.configuration = config if config else CellularAtomataMapGenerator.Configuration()
-        self.tiles = make_grid(bounds.size)
+        self.tiles = np.full((bounds.size.height, bounds.size.width), fill_value=Empty, dtype=tile_datatype, order='C')
 
     def generate(self):
         '''
@@ -59,14 +62,23 @@ class CellularAtomataMapGenerator:
         self._fill()
         self._run_atomaton()
 
+    def apply(self, map: 'Map'):
+        origin = self.bounds.origin
+        for y, x in np.ndindex(self.tiles.shape):
+            map_pt = origin + Vector(x, y)
+            tile = self.tiles[y, x]
+            if tile == Floor:
+                map.tiles[map_pt.numpy_index] = tile
+
     def _fill(self):
         fill_percentage = self.configuration.fill_percentage
 
         for y, x in np.ndindex(self.tiles.shape):
-            self.tiles[x, y] = Floor if random.random() < fill_percentage else Wall
+            self.tiles[y, x] = Floor if random.random() < fill_percentage else Empty
 
     def _run_atomaton(self):
-        alternate_tiles = make_grid(self.bounds.size)
+        alternate_tiles = np.full((self.bounds.size.height, self.bounds.size.width),
+                                  fill_value=Empty, dtype=tile_datatype, order='C')
 
         number_of_rounds = self.configuration.number_of_rounds
         if number_of_rounds < 1:
@@ -100,21 +112,22 @@ class CellularAtomataMapGenerator:
             # Start with 1 because the point is its own neighbor
             number_of_neighbors = 1
             for neighbor in pt.neighbors:
-                if neighbor not in self.bounds:
-                    continue
+                try:
+                    if from_tiles[neighbor.y, neighbor.x] == Floor:
+                        number_of_neighbors += 1
+                except IndexError:
+                    pass
 
-                if from_tiles[neighbor.x, neighbor.y] == Floor:
-                    number_of_neighbors += 1
-
-            tile_is_alive = from_tiles[pt.x, pt.y] == Floor
+            idx = (pt.y, pt.x)
+            tile_is_alive = from_tiles[idx] == Floor
             if tile_is_alive and number_of_neighbors >= 5:
                 # Survival
-                to_tiles[pt.x, pt.y] = Floor
+                to_tiles[idx] = Floor
             elif not tile_is_alive and number_of_neighbors >= 5:
                 # Birth
-                to_tiles[pt.x, pt.y] = Floor
+                to_tiles[idx] = Floor
             else:
-                to_tiles[pt.x, pt.y] = Wall
+                to_tiles[idx] = Empty
 
     def __str__(self):
         return '\n'.join(''.join(chr(i['light']['ch']) for i in row) for row in self.tiles)
diff --git a/erynrl/map/generator/room.py b/erynrl/map/generator/room.py
index 3cc534b..d0ee4e9 100644
--- a/erynrl/map/generator/room.py
+++ b/erynrl/map/generator/room.py
@@ -5,12 +5,14 @@ import random
 from dataclasses import dataclass
 from typing import Iterable, Iterator, List, Optional, Tuple, TYPE_CHECKING
 
+import numpy as np
 import tcod
 
 from ... import log
 from ...geometry import Point, Rect, Size
-from ..room import RectangularRoom, Room
-from ..tile import Empty, Floor, StairsDown, StairsUp, Wall
+from ..room import FreeformRoom, RectangularRoom, Room
+from ..tile import Empty, Floor, StairsDown, StairsUp, Wall, tile_datatype
+from .cellular_atomata import CellularAtomataMapGenerator
 
 if TYPE_CHECKING:
     from .. import Map
@@ -196,6 +198,45 @@ class RectangularRoomMethod(RoomMethod):
         return RectangularRoom(rect)
 
 
+class CellularAtomatonRoomMethod(RoomMethod):
+
+    def __init__(self, cellular_atomaton_config: CellularAtomataMapGenerator.Configuration):
+        self.cellular_atomaton_configuration = cellular_atomaton_config
+
+    def room_in_rect(self, rect: Rect) -> Optional[Room]:
+        # The cellular atomaton doesn't generate any walls, just floors and
+        # emptiness. Inset it by 1 all the way around so that we can draw walls
+        # around it.
+
+        atomaton_rect = rect.inset_rect(1, 1, 1, 1)
+        room_generator = CellularAtomataMapGenerator(atomaton_rect, self.cellular_atomaton_configuration)
+        room_generator.generate()
+
+        # Create a new tile array and copy the result of the atomaton into it,
+        # then draw walls everywhere that neighbors a floor tile.
+
+        width = rect.width
+        height = rect.height
+
+        room_tiles = np.full((height, width), fill_value=Empty, dtype=tile_datatype, order='C')
+        room_tiles[1:height - 1, 1:width - 1] = room_generator.tiles
+
+        for y, x in np.ndindex(room_tiles.shape):
+            if room_tiles[y, x] == Floor:
+                continue
+
+            for neighbor in Point(x, y).neighbors:
+                try:
+                    if room_tiles[neighbor.y, neighbor.x] != Floor:
+                        continue
+                    room_tiles[y, x] = Wall
+                    break
+                except IndexError:
+                    pass
+
+        return FreeformRoom(rect, room_tiles)
+
+
 class OrRoomMethod(RoomMethod):
     '''
     A room generator method that picks between several RoomMethods at random
diff --git a/erynrl/map/room.py b/erynrl/map/room.py
index 0e8ddce..5228620 100644
--- a/erynrl/map/room.py
+++ b/erynrl/map/room.py
@@ -4,9 +4,12 @@
 Implements an abstract Room class, and subclasses that implement it. Rooms are basic components of maps.
 '''
 
-from typing import Iterator
+from typing import Iterable
 
-from ..geometry import Point, Rect
+import numpy as np
+
+from ..geometry import Point, Rect, Vector
+from .tile import Floor, Wall
 
 
 class Room:
@@ -21,17 +24,17 @@ class Room:
         return self.bounds.midpoint
 
     @property
-    def wall_points(self) -> Iterator[Point]:
+    def wall_points(self) -> Iterable[Point]:
         '''An iterator over all the points that make up the walls of this room.'''
         raise NotImplementedError()
 
     @property
-    def floor_points(self) -> Iterator[Point]:
+    def floor_points(self) -> Iterable[Point]:
         '''An iterator over all the points that make of the floor of this room'''
         raise NotImplementedError()
 
     @property
-    def walkable_tiles(self) -> Iterator[Point]:
+    def walkable_tiles(self) -> Iterable[Point]:
         '''An iterator over all the points that are walkable in this room.'''
         raise NotImplementedError()
 
@@ -47,14 +50,14 @@ class RectangularRoom(Room):
     '''
 
     @property
-    def walkable_tiles(self) -> Iterator[Point]:
+    def walkable_tiles(self) -> Iterable[Point]:
         floor_rect = self.bounds.inset_rect(top=1, right=1, bottom=1, left=1)
         for y in range(floor_rect.min_y, floor_rect.max_y + 1):
             for x in range(floor_rect.min_x, floor_rect.max_x + 1):
                 yield Point(x, y)
 
     @property
-    def wall_points(self) -> Iterator[Point]:
+    def wall_points(self) -> Iterable[Point]:
         bounds = self.bounds
 
         min_y = bounds.min_y
@@ -71,7 +74,7 @@ class RectangularRoom(Room):
             yield Point(max_x, y)
 
     @property
-    def floor_points(self) -> Iterator[Point]:
+    def floor_points(self) -> Iterable[Point]:
         inset_bounds = self.bounds.inset_rect(1, 1, 1, 1)
 
         min_y = inset_bounds.min_y
@@ -85,3 +88,30 @@ class RectangularRoom(Room):
 
     def __repr__(self) -> str:
         return f'{self.__class__.__name__}({self.bounds})'
+
+
+class FreeformRoom(Room):
+    def __init__(self, bounds: Rect, tiles: np.ndarray):
+        super().__init__(bounds)
+        self.tiles = tiles
+
+    @property
+    def floor_points(self) -> Iterable[Point]:
+        room_origin_vector = Vector.from_point(self.bounds.origin)
+        for y, x in np.ndindex(self.tiles.shape):
+            if self.tiles[y, x] == Floor:
+                yield Point(x, y) + room_origin_vector
+
+    @property
+    def wall_points(self) -> Iterable[Point]:
+        room_origin_vector = Vector.from_point(self.bounds.origin)
+        for y, x in np.ndindex(self.tiles.shape):
+            if self.tiles[y, x] == Wall:
+                yield Point(x, y) + room_origin_vector
+
+    @property
+    def walkable_tiles(self) -> Iterable[Point]:
+        room_origin_vector = Vector.from_point(self.bounds.origin)
+        for y, x in np.ndindex(self.tiles.shape):
+            if self.tiles[y, x]['walkable']:
+                yield Point(x, y) + room_origin_vector