diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b663cb0..1d1ee26d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -161,6 +161,7 @@ add_library(lego1 SHARED
   LEGO1/mxramstreamcontroller.cpp
   LEGO1/mxramstreamprovider.cpp
   LEGO1/mxregion.cpp
+  LEGO1/mxregionlist.cpp
   LEGO1/mxscheduler.cpp
   LEGO1/mxsemaphore.cpp
   LEGO1/mxsmkpresenter.cpp
diff --git a/LEGO1/mxregion.cpp b/LEGO1/mxregion.cpp
index d16a1504..ac2353ba 100644
--- a/LEGO1/mxregion.cpp
+++ b/LEGO1/mxregion.cpp
@@ -1,11 +1,24 @@
 #include "mxregion.h"
 
+#include <limits.h>
+
 DECOMP_SIZE_ASSERT(MxRegion, 0x1c);
 
-// OFFSET: LEGO1 0x100c31c0 STUB
+// OFFSET: LEGO1 0x100c31c0
 MxRegion::MxRegion()
+{
+  m_list = new MxRegionList;
+  m_rect.m_left = INT_MAX;
+  m_rect.m_top = INT_MAX;
+  m_rect.m_right = -1;
+  m_rect.m_bottom = - 1;
+}
+
+// OFFSET: LEGO1 0x100c3660 STUB
+MxBool MxRegion::vtable20()
 {
   // TODO
+  return FALSE;
 }
 
 // OFFSET: LEGO1 0x100c3690 STUB
@@ -31,10 +44,3 @@ void MxRegion::vtable1c()
 {
   // TODO
 }
-
-// OFFSET: LEGO1 0x100c3660 STUB
-MxBool MxRegion::vtable20()
-{
-  // TODO
-  return FALSE;
-}
\ No newline at end of file
diff --git a/LEGO1/mxregion.h b/LEGO1/mxregion.h
index f68139a0..64e4c9e2 100644
--- a/LEGO1/mxregion.h
+++ b/LEGO1/mxregion.h
@@ -2,9 +2,25 @@
 #define MXREGION_H
 
 #include "mxcore.h"
+#include "mxregionlist.h"
 #include "mxrect32.h"
 #include "decomp.h"
 
+// SIZE 0x0c
+struct MxRegionTopBottom
+{
+  MxS32 m_top;
+  MxS32 m_bottom;
+  MxRegionLeftRightList *m_leftRightList;
+};
+
+// SIZE 0x08
+struct MxRegionLeftRight
+{
+  MxS32 m_left;
+  MxS32 m_right;
+};
+
 // VTABLE 0x100dcae8
 // SIZE 0x1c
 class MxRegion : public MxCore
@@ -21,9 +37,7 @@ public:
   inline MxRect32 &GetRect() { return this->m_rect; }
 
 private:
-  // A container (probably MxList) holding MxRect32
-  // MxList<MxRect32*> *m_rects;
-  undefined4 m_unk08;
+  MxRegionList *m_list;
   MxRect32 m_rect;
 };
 
diff --git a/LEGO1/mxregionlist.cpp b/LEGO1/mxregionlist.cpp
new file mode 100644
index 00000000..a25cda73
--- /dev/null
+++ b/LEGO1/mxregionlist.cpp
@@ -0,0 +1,18 @@
+#include "mxregionlist.h"
+#include "mxregion.h"
+
+// OFFSET: LEGO1 0x100c4e80
+void MxRegionLeftRightListParent::Destroy(MxRegionLeftRight *p_leftRight)
+{
+  delete p_leftRight;
+}
+
+// OFFSET: LEGO1 0x100c33e0
+void MxRegionListParent::Destroy(MxRegionTopBottom *p_topBottom)
+{
+  if (p_topBottom) {
+    if (p_topBottom->m_leftRightList)
+      delete p_topBottom->m_leftRightList;
+    delete p_topBottom;
+  }
+}
\ No newline at end of file
diff --git a/LEGO1/mxregionlist.h b/LEGO1/mxregionlist.h
new file mode 100644
index 00000000..1dcc8865
--- /dev/null
+++ b/LEGO1/mxregionlist.h
@@ -0,0 +1,41 @@
+#ifndef MXREGIONLIST_H
+#define MXREGIONLIST_H
+
+#include "mxlist.h"
+
+struct MxRegionLeftRight;
+struct MxRegionTopBottom;
+
+// VTABLE 0x100dcc70
+// SIZE 0x18
+class MxRegionLeftRightListParent : public MxList<MxRegionLeftRight*>
+{
+public:
+  static void Destroy(MxRegionLeftRight *p_leftRight);
+
+  MxRegionLeftRightListParent() {
+    m_customDestructor = Destroy;
+  }
+};
+
+// VTABLE 0x100dcc88
+// SIZE 0x18
+class MxRegionLeftRightList : public MxRegionLeftRightListParent {};
+
+// VTABLE 0x100dcb40
+// SIZE 0x18
+class MxRegionListParent : public MxList<MxRegionTopBottom*>
+{
+public:
+  static void Destroy(MxRegionTopBottom *p_topBottom);
+
+  MxRegionListParent() {
+    m_customDestructor = Destroy;
+  }
+};
+
+// VTABLE 0x100dcb58
+// SIZE 0x18
+class MxRegionList : public MxRegionListParent {};
+
+#endif // MXREGIONLIST_H