diff --git a/src/world/generation/feature/arcology/arcology.tscn b/src/world/generation/feature/arcology/arcology.tscn
index b31b108..fdfda0d 100644
--- a/src/world/generation/feature/arcology/arcology.tscn
+++ b/src/world/generation/feature/arcology/arcology.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=8 format=3 uid="uid://nllc8ljmn37g"]
+[gd_scene load_steps=10 format=3 uid="uid://nllc8ljmn37g"]
 
 [ext_resource type="Script" uid="uid://drk82eeqk2mjs" path="res://src/world/generation/feature/generation_feature.gd" id="1_ek7o7"]
 [ext_resource type="Material" uid="uid://0ja682cfcvu3" path="res://assets/materials/shaders/megalith_base.material" id="2_pko82"]
@@ -12,9 +12,18 @@ size = Vector2(100000, 100000)
 [sub_resource type="ConcavePolygonShape3D" id="ConcavePolygonShape3D_ek7o7"]
 data = PackedVector3Array(50000, 0, 50000, -50000, 0, 50000, 50000, 0, -50000, -50000, 0, 50000, -50000, 0, -50000, 50000, 0, -50000)
 
-[node name="Arcology" type="Node3D" node_paths=PackedStringArray("sub_layers")]
+[sub_resource type="Curve" id="Curve_0w44q"]
+_limits = [1.0, 4.0, 0.0, 1.0]
+_data = [Vector2(0, 4), 0.0, -7.386, 0, 0, Vector2(1, 1), 0.0, 0.0, 0, 0]
+point_count = 2
+
+[sub_resource type="Curve" id="Curve_amoo5"]
+_limits = [1.0, 4.0, 0.0, 1.0]
+_data = [Vector2(0, 1), 0.0, 0.0, 0, 0, Vector2(1, 4), 0.0, 0.0, 0, 0]
+point_count = 2
+
+[node name="Arcology" type="Node3D"]
 script = ExtResource("1_ek7o7")
-sub_layers = [NodePath("MetroGridLayer"), NodePath("MetroGridLayer2"), NodePath("MetroGridLayer3"), NodePath("MetroGridLayer4")]
 metadata/_custom_type_script = "uid://drk82eeqk2mjs"
 
 [node name="InnerPyramid" type="CSGCylinder3D" parent="."]
@@ -81,21 +90,109 @@ script = ExtResource("4_kox75")
 end_margin_pct = 0.01
 metadata/_custom_type_script = "uid://cv0o1lirqeq44"
 
-[node name="MetroGridLayer" parent="." instance=ExtResource("4_fy7wq")]
-simple_construct_threshold = 0.3
-bounding_box = AABB(0, 0, 0, 99497, 100, 503)
+[node name="MetroQuadrant" type="Node3D" parent="."]
 
-[node name="MetroGridLayer2" parent="." instance=ExtResource("4_fy7wq")]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 99497, 0, 0)
-simple_construct_threshold = 0.3
-bounding_box = AABB(0, 0, 0, 503, 100, 99497)
+[node name="OuterMetro" type="Node3D" parent="MetroQuadrant"]
 
-[node name="MetroGridLayer3" parent="." instance=ExtResource("4_fy7wq")]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 503, 0, 99497)
-simple_construct_threshold = 0.3
-bounding_box = AABB(0, 0, 0, 99497, 100, 503)
+[node name="MetroGridLayer" parent="MetroQuadrant/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 55)
+bounding_box = AABB(0, 0, 0, 49088, 100, 448)
 
-[node name="MetroGridLayer4" parent="." instance=ExtResource("4_fy7wq")]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 503)
-simple_construct_threshold = 0.3
-bounding_box = AABB(0, 0, 0, 503, 100, 99497)
+[node name="MetroGridLayer2" parent="MetroQuadrant/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 503)
+bounding_box = AABB(0, 0, 0, 448, 100, 48640)
+
+[node name="InnerMetro" type="Node3D" parent="MetroQuadrant"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 45047, 0, 503)
+construct_height_factor_x = SubResource("Curve_0w44q")
+construct_height_factor_z = SubResource("Curve_amoo5")
+bounding_box = AABB(0, 0, 0, 4096, 100, 44480)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 503, 0, 45047)
+construct_height_factor_x = SubResource("Curve_amoo5")
+construct_height_factor_z = SubResource("Curve_0w44q")
+bounding_box = AABB(0, 0, 0, 44480, 100, 4096)
+
+[node name="MetroQuadrant2" type="Node3D" parent="."]
+transform = Transform3D(-4.371139e-08, 0, 1, 0, 1, 0, -1, 0, -4.371139e-08, 0, 0, 100000)
+
+[node name="OuterMetro" type="Node3D" parent="MetroQuadrant2"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant2/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 55)
+bounding_box = AABB(0, 0, 0, 49088, 100, 448)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant2/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 503)
+bounding_box = AABB(0, 0, 0, 448, 100, 48640)
+
+[node name="InnerMetro" type="Node3D" parent="MetroQuadrant2"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant2/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 45047, 0, 503)
+construct_height_factor_x = SubResource("Curve_0w44q")
+construct_height_factor_z = SubResource("Curve_amoo5")
+bounding_box = AABB(0, 0, 0, 4096, 100, 44480)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant2/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 503, 0, 45047)
+construct_height_factor_x = SubResource("Curve_amoo5")
+construct_height_factor_z = SubResource("Curve_0w44q")
+bounding_box = AABB(0, 0, 0, 44480, 100, 4096)
+
+[node name="MetroQuadrant3" type="Node3D" parent="."]
+transform = Transform3D(-1, 0, -8.742278e-08, 0, 1, 0, 8.742278e-08, 0, -1, 100000, 0, 100000)
+
+[node name="OuterMetro" type="Node3D" parent="MetroQuadrant3"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant3/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 55)
+bounding_box = AABB(0, 0, 0, 49088, 100, 448)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant3/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 503)
+bounding_box = AABB(0, 0, 0, 448, 100, 48640)
+
+[node name="InnerMetro" type="Node3D" parent="MetroQuadrant3"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant3/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 45047, 0, 503)
+construct_height_factor_x = SubResource("Curve_0w44q")
+construct_height_factor_z = SubResource("Curve_amoo5")
+bounding_box = AABB(0, 0, 0, 4096, 100, 44480)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant3/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 503, 0, 45047)
+construct_height_factor_x = SubResource("Curve_amoo5")
+construct_height_factor_z = SubResource("Curve_0w44q")
+bounding_box = AABB(0, 0, 0, 44480, 100, 4096)
+
+[node name="MetroQuadrant4" type="Node3D" parent="."]
+transform = Transform3D(-4.371139e-08, 0, -1, 0, 1, 0, 1, 0, -4.371139e-08, 100000, 0, 0)
+
+[node name="OuterMetro" type="Node3D" parent="MetroQuadrant4"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant4/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 55)
+bounding_box = AABB(0, 0, 0, 49088, 100, 448)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant4/OuterMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 55, 0, 503)
+bounding_box = AABB(0, 0, 0, 448, 100, 48640)
+
+[node name="InnerMetro" type="Node3D" parent="MetroQuadrant4"]
+
+[node name="MetroGridLayer" parent="MetroQuadrant4/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 45047, 0, 503)
+construct_height_factor_x = SubResource("Curve_0w44q")
+construct_height_factor_z = SubResource("Curve_amoo5")
+bounding_box = AABB(0, 0, 0, 4096, 100, 44480)
+
+[node name="MetroGridLayer2" parent="MetroQuadrant4/InnerMetro" instance=ExtResource("4_fy7wq")]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 503, 0, 45047)
+construct_height_factor_x = SubResource("Curve_amoo5")
+construct_height_factor_z = SubResource("Curve_0w44q")
+bounding_box = AABB(0, 0, 0, 44480, 100, 4096)
diff --git a/src/world/generation/feature/generation_feature.gd b/src/world/generation/feature/generation_feature.gd
index 06c9812..28580cb 100644
--- a/src/world/generation/feature/generation_feature.gd
+++ b/src/world/generation/feature/generation_feature.gd
@@ -6,11 +6,27 @@ class_name GenerationFeature extends Node3D
 @export var noise_scale := Vector3.ONE
 @export var noise_offset := Vector3.ZERO
 
-@export var sub_layers: Array[GenerationLayer]
-
+var sub_layers: Array[GenerationLayer]:
+	get():
+		if not _defined_sub_layers:
+			sub_layers = _find_sub_layers(self)
+			_defined_sub_layers = true
+		return sub_layers
+var _defined_sub_layers := false
 var _generated := false
 
 
+func _find_sub_layers(node: Node) -> Array[GenerationLayer]:
+	var layers: Array[GenerationLayer] = []
+	if node is GenerationLayer:
+		layers.append(node)
+	for c: Node in node.get_children():
+		# Do not walk outside of this scene
+		if c.owner in [owner, self]:
+			layers.append_array(_find_sub_layers(c))
+	return layers
+
+
 func probe() -> void:
 	# TODO may want to make low-detail & high-detail probes distinct
 	if not _generated:
diff --git a/src/world/generation/layer/grid_layer/grid_layer.gd b/src/world/generation/layer/grid_layer/grid_layer.gd
index dc7caa1..cbd1570 100644
--- a/src/world/generation/layer/grid_layer/grid_layer.gd
+++ b/src/world/generation/layer/grid_layer/grid_layer.gd
@@ -42,8 +42,10 @@ func probe_radius(center: Vector3, radius: float) -> void:
 	var rad_diff := Vector3(radius, 0, radius)
 
 	# Translate probe box limits to grid space
-	var grid_low := world_to_local(center - rad_diff).floor()
-	var grid_high := world_to_local(center + rad_diff).floor()
+	var a := world_to_local(center - rad_diff).floor()
+	var b := world_to_local(center + rad_diff).floor()
+	var grid_low := Vector2(minf(a.x, b.x), minf(a.y, b.y))
+	var grid_high := Vector2(maxf(a.x, b.x), maxf(a.y, b.y))
 	var grid_max := _plane_size().floor()
 
 	# Constrain to bounding box
@@ -96,7 +98,6 @@ func _init_debug_draw() -> void:
 	_debug_box = BoxMesh.new()
 	var mat := StandardMaterial3D.new()
 	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
-	mat.cull_mode = BaseMaterial3D.CULL_DISABLED
 	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
 	_debug_box.material = mat
 	_debug_meshinstance = MeshInstance3D.new()
diff --git a/src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd b/src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd
index b407996..c6e7c2c 100644
--- a/src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd
+++ b/src/world/generation/layer/metro_grid_layer/metro_grid_layer.gd
@@ -9,7 +9,7 @@ extends GridLayer
 @export var noise_offset := Vector3.ZERO
 
 @export_group("Construct Parameters")
-@export var simple_construct_threshold := 0.4
+@export var simple_construct_threshold := 0.3
 @export var construct_height_factor_x: Curve
 @export var construct_height_factor_z: Curve