diff --git a/src/main/java/net/Chipperfluff/chipi/ChipiMod.java b/src/main/java/net/Chipperfluff/chipi/ChipiMod.java
index 5c2901d..c316572 100644
--- a/src/main/java/net/Chipperfluff/chipi/ChipiMod.java
+++ b/src/main/java/net/Chipperfluff/chipi/ChipiMod.java
@@ -32,6 +32,7 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.GameRules;
 import net.minecraft.world.World;
 import net.minecraft.world.gen.GenerationStep;
+import net.Chipperfluff.chipi.command.CommandHandler;
 
 public class ChipiMod implements ModInitializer {
 
@@ -54,6 +55,7 @@ public class ChipiMod implements ModInitializer {
         ModEffects.register();
         ChipiBlessingEvents.register();
         ChipiHungerHandler.register();
+        CommandHandler.register();
 
         FabricDefaultAttributeRegistry.register(ModEntities.MEP, MepEntity.createMepAttributes());
 
@@ -63,10 +65,6 @@ public class ChipiMod implements ModInitializer {
             RegistryKey.of(RegistryKeys.PLACED_FEATURE, new Identifier("chipi", "chipper_ore"))
         );
 
-        CommandRegistrationCallback.EVENT.register((dispatcher, registryAccess, environment) -> {
-            ChpCommand.register(dispatcher);
-        });
-
         ServerLifecycleEvents.SERVER_STARTED.register(server -> {
             SERVER = server;
         });
diff --git a/src/main/java/net/Chipperfluff/chipi/command/CommandHandler.java b/src/main/java/net/Chipperfluff/chipi/command/CommandHandler.java
new file mode 100644
index 0000000..a059710
--- /dev/null
+++ b/src/main/java/net/Chipperfluff/chipi/command/CommandHandler.java
@@ -0,0 +1,18 @@
+package net.Chipperfluff.chipi.command;
+
+import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback;
+import net.minecraft.server.command.ServerCommandSource;
+
+public final class CommandHandler {
+
+    private CommandHandler() {}
+
+    public static void register() {
+        CommandRegistrationCallback.EVENT.register(
+            (dispatcher, registryAccess, environment) -> {
+                ChpCommand.register(dispatcher);
+                CspCommand.register(dispatcher);
+            }
+        );
+    }
+}
diff --git a/src/main/java/net/Chipperfluff/chipi/command/CspCommand.java b/src/main/java/net/Chipperfluff/chipi/command/CspCommand.java
new file mode 100644
index 0000000..a88861f
--- /dev/null
+++ b/src/main/java/net/Chipperfluff/chipi/command/CspCommand.java
@@ -0,0 +1,65 @@
+package net.Chipperfluff.chipi.command;
+
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.arguments.StringArgumentType;
+import com.mojang.brigadier.context.CommandContext;
+
+import net.Chipperfluff.chipi.world.gen.struct.ChipiStructures;
+import net.minecraft.command.CommandSource;
+import net.minecraft.command.argument.BlockPosArgumentType;
+import net.minecraft.server.command.CommandManager;
+import net.minecraft.server.command.ServerCommandSource;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.text.Text;
+import net.minecraft.util.math.BlockPos;
+
+public class CspCommand {
+
+    public static void register(CommandDispatcher<ServerCommandSource> dispatcher) {
+        dispatcher.register(
+            CommandManager.literal("csp")
+            .then(
+                CommandManager.argument("name", StringArgumentType.word())
+                .suggests((ctx, builder) ->
+                    CommandSource.suggestMatching(ChipiStructures.getNames(), builder))
+                .then(
+                    CommandManager.argument("center", BlockPosArgumentType.blockPos())
+                    .then(
+                        CommandManager.argument("worldPos", BlockPosArgumentType.blockPos())
+                        .executes(ctx -> execute(ctx))
+                    )
+                )
+            )
+        );
+    }
+
+    private static int execute(CommandContext<ServerCommandSource> ctx) {
+        ServerCommandSource source = ctx.getSource();
+        ServerWorld world = source.getWorld();
+
+        String name = StringArgumentType.getString(ctx, "name");
+        BlockPos center = BlockPosArgumentType.getBlockPos(ctx, "center");
+        BlockPos worldPos = BlockPosArgumentType.getBlockPos(ctx, "worldPos");
+
+        var structure = ChipiStructures.get(name);
+
+        if (structure == null) {
+            source.sendError(Text.literal("Unknown structure: " + name));
+            return 0;
+        }
+
+        BlockPos local = structure.worldToLocal(center, worldPos);
+
+        source.sendFeedback(
+            () -> Text.literal(
+                "localPos = (" +
+                local.getX() + ", " +
+                local.getY() + ", " +
+                local.getZ() + ")"
+            ),
+            false
+        );
+
+        return 1;
+    }
+}
diff --git a/src/main/java/net/Chipperfluff/chipi/world/gen/ChipiStructure.java b/src/main/java/net/Chipperfluff/chipi/world/gen/ChipiStructure.java
index 2600010..0d3a840 100644
--- a/src/main/java/net/Chipperfluff/chipi/world/gen/ChipiStructure.java
+++ b/src/main/java/net/Chipperfluff/chipi/world/gen/ChipiStructure.java
@@ -62,6 +62,18 @@ public abstract class ChipiStructure {
     }
 
     public BlockPos localToWorld(BlockPos structureOrigin, BlockPos localPos) {
-        return structureOrigin.add(deltaX + localPos.getX(), deltaY + localPos.getY(), deltaZ + localPos.getZ());
+        return structureOrigin.add(
+            deltaX + localPos.getX(),
+            deltaY + localPos.getY(),
+            deltaZ + localPos.getZ()
+        );
+    }
+
+    public BlockPos worldToLocal(BlockPos structureOrigin, BlockPos worldPos) {
+        return new BlockPos(
+            worldPos.getX() - structureOrigin.getX() - deltaX,
+            worldPos.getY() - structureOrigin.getY() - deltaY,
+            worldPos.getZ() - structureOrigin.getZ() - deltaZ
+        );
     }
 }
diff --git a/src/main/java/net/Chipperfluff/chipi/world/gen/DungeonContext.java b/src/main/java/net/Chipperfluff/chipi/world/gen/DungeonContext.java
index abf5bba..ce35219 100644
--- a/src/main/java/net/Chipperfluff/chipi/world/gen/DungeonContext.java
+++ b/src/main/java/net/Chipperfluff/chipi/world/gen/DungeonContext.java
@@ -10,7 +10,7 @@ public final class DungeonContext {
 
     private Integer grid_x;
     private Integer grid_y;
-    private BlockPos structure_origin;
+    private BlockPos structure_origin; // logical center
     private ChipiStructure structure;
     private ServerWorld world;
 
@@ -44,6 +44,10 @@ public final class DungeonContext {
         return structure;
     }
 
+    public BlockPos getStructureOrigin() {
+        return structure_origin;
+    }
+
     public void setBlock(BlockPos localPos, BlockState state) {
         BlockPos worldPos = structure.localToWorld(structure_origin, localPos);
         System.out.println("[CHIPI] setBlock grid=(" + grid_x + "," + grid_y + ") worldPos=" + worldPos);
diff --git a/src/main/java/net/Chipperfluff/chipi/world/gen/WorldMaster.java b/src/main/java/net/Chipperfluff/chipi/world/gen/WorldMaster.java
index a1e2d79..408de35 100644
--- a/src/main/java/net/Chipperfluff/chipi/world/gen/WorldMaster.java
+++ b/src/main/java/net/Chipperfluff/chipi/world/gen/WorldMaster.java
@@ -35,11 +35,9 @@ public final class WorldMaster {
     }
 
     public static RoomBaseStructure afterPlaceRoom(DungeonContext ctx) {
-
         if (ctx.getGridX() == 1 && ctx.getGridY() == 1) {
-            ctx.setBlock(new BlockPos(0, 0, 0), Blocks.REDSTONE_BLOCK.getDefaultState());
+            ctx.setBlock(new BlockPos(9, 1, 8), Blocks.REDSTONE_BLOCK.getDefaultState());
         }
-
         return getDefaultRoom();
     }