diff --git a/bigstuff.cpp b/bigstuff.cpp
index f87c80ab..2803e572 100644
--- a/bigstuff.cpp
+++ b/bigstuff.cpp
@@ -142,6 +142,7 @@ void generateAlts(heptagon *h, int levs) {
       continue;
       }
     ho->alt = hm;
+    hm->cdata = (cdata*) ho;
     if(levs) generateAlts(ho, levs-1);
     }
   }
@@ -199,6 +200,7 @@ heptagon *createAlternateMap(cell *c, int rad, hstate firststate, int special) {
   alt->c7 = NULL;
   alt->alt = alt;
   h->alt = alt;
+  alt->cdata = (cdata*) h;
   
   for(int d=rad; d>=0; d--) {
     generateAlts(cx[d]->master);  
diff --git a/cell.cpp b/cell.cpp
index 5d190a25..28a754ee 100644
--- a/cell.cpp
+++ b/cell.cpp
@@ -839,6 +839,10 @@ void clearcell(cell *c) {
 heptagon deletion_marker;
 
 void clearHexes(heptagon *at) {
+  if(at->c7 && at->cdata) {
+    delete at->cdata;
+    at->cdata = NULL;
+    }
   if(at->c7) {
     if(!nonbitrunc) for(int i=0; i<S7; i++)
       clearcell(at->c7->mov[i]);
@@ -849,6 +853,10 @@ void clearHexes(heptagon *at) {
 void clearfrom(heptagon *at) {
   queue<heptagon*> q;
   q.push(at);
+  if(at->alt && at->c7) {
+    printf("disconnect %p -> %p (from real)\n", at, at->alt);
+    at->alt->cdata = NULL;
+    }
   at->alt = &deletion_marker;
 //int maxq = 0;
   while(!q.empty()) {
@@ -856,9 +864,21 @@ void clearfrom(heptagon *at) {
 //  if(q.size() > maxq) maxq = q.size();
     q.pop();
     DEBMEM ( printf("from %p\n", at); )
+    if(!at->c7) {
+      heptagon *h = (heptagon*) at->cdata;
+      if(h) {
+        if(h->alt != at) printf("alt error :: h->alt = %p\n", h->alt);
+        cell *c = h->c7;
+        destroycellcontents(c);
+        forCellEx(c2, c) destroycellcontents(c2);
+        h->alt = NULL;
+        at->cdata = NULL;
+        }
+      }
     for(int i=0; i<S7; i++) if(at->move[i]) {
       if(at->move[i]->alt != &deletion_marker)
         q.push(at->move[i]);    
+      if(at->move[i]->alt && at->move[i]->c7) at->move[i]->alt->cdata = NULL;
       at->move[i]->alt = &deletion_marker;
       DEBMEM ( printf("!mov %p [%p]\n", at->move[i], at->move[i]->move[at->spin(i)]); )
       if(at->move[i]->move[at->spin(i)] != NULL &&
@@ -1381,8 +1401,11 @@ int celldistance(cell *c1, cell *c2) {
   }
 
 void clearCellMemory() {
-  for(int i=0; i<size(allmaps); i++) delete allmaps[i];
+  for(int i=0; i<size(allmaps); i++) 
+    if(allmaps[i])
+      delete allmaps[i];
   allmaps.clear();
+  last_cleared = NULL;
   }
 
 auto cellhooks = addHook(clearmemory, 500, clearCellMemory);
diff --git a/classes.cpp b/classes.cpp
index bf954b34..7780bc5b 100644
--- a/classes.cpp
+++ b/classes.cpp
@@ -1604,6 +1604,12 @@ const landtype linf[landtypes] = {
   { 0x306030, "Ruined City", ruindesc},
   { 0x306030, "Magnetosphere", NODESCYET},
   { 0x306030, "Jelly Kingdom", jellydesc},
+  { 0xFF00FF, "Lost Memory", 
+    "Because of the properties of hyperbolic geometry, it is extremely unlikely to randomly "
+    "get back to a faraway place you have been to. However, you have managed to get there "
+    "somehow. In the meantime, its memory has been cleared, since the 'remove faraway cells from the memory'"
+    " option was on."
+    },
   };
 
 struct landtacinfo { eLand l; int tries, multiplier; };
diff --git a/classes.h b/classes.h
index 2c72cf26..02cd14c3 100644
--- a/classes.h
+++ b/classes.h
@@ -164,7 +164,7 @@ enum eWall { waNone, waIcewall, waBarrier, waFloorA, waFloorB, waCavewall, waCav
   waDock, waBurningDock, waRuinWall
   };
 
-static const int landtypes = 83;
+static const int landtypes = 84;
 
 struct landtype {
   int color;
@@ -191,7 +191,7 @@ enum eLand { laNone, laBarrier, laCrossroads, laDesert, laIce, laCaves, laJungle
   laMirrorOld,
   laVolcano, laBlizzard, laHunting, laTerracotta, laMercuryRiver,
   laDual, laSnakeNest, laDocks, laRuins, laMagnetic,
-  laSwitch
+  laSwitch, laMemory
   };
 
 enum eGeometry {gNormal, gEuclid, gSphere, gElliptic, gQuotient, gQuotient2, gTorus, gOctagon, g45, g46, g47, gSmallSphere, gTinySphere, gEuclidSquare, gGUARD};
diff --git a/compileunits.h b/compileunits.h
index bbd96359..3a45a315 100644
--- a/compileunits.h
+++ b/compileunits.h
@@ -33,6 +33,7 @@
 #include "flags.cpp"
 #include "yendor.cpp"
 #include "complex.cpp"
+#include "savemem.cpp"
 #include "game.cpp"
 #include "orbgen.cpp"
 #include "monstergen.cpp"
diff --git a/config.cpp b/config.cpp
index a40b60fa..8b2373b1 100644
--- a/config.cpp
+++ b/config.cpp
@@ -268,6 +268,8 @@ void initConfig() {
   addsaver(geom3::tc_alpha, "3D TC alpha");
   addsaver(geom3::highdetail, "3D highdetail");
   addsaver(geom3::middetail, "3D middetail");
+  
+  addsaver(memory_saving_mode, "memory_saving_mode", (ISMOBILE || ISPANDORA) ? 1 : 0);
 
   addsaver(rug::renderonce, "rug-renderonce");
   addsaver(rug::rendernogl, "rug-rendernogl");
@@ -665,6 +667,7 @@ void showGraphConfig() {
   dialog::addSelItem(XLAT("font scale"), its(fontscale), 'b');
 
   dialog::addSelItem(XLAT("sight range"), its(sightrange), 'r');
+  dialog::addSelItem(XLAT("remove faraway cells from memory"), its(memory_saving_mode), 'y');
 
   dialog::addSelItem(XLAT("compass size"), its(vid.mobilecompasssize), 'c');
 
@@ -684,6 +687,8 @@ void showGraphConfig() {
     if(xuni == 'u') vid.particles = !vid.particles;
     if(xuni == 'd') vid.graphglyph = (1+vid.graphglyph)%3;
     
+    if(xuni == 'y') memory_saving_mode = !memory_saving_mode;
+    
     if(xuni == 'j') {
       dialog::editNumber(whatever, -10, 10, 1, 0, XLAT("whatever"), 
         XLAT("Whatever."));
diff --git a/game.cpp b/game.cpp
index a335da8b..46f3d586 100644
--- a/game.cpp
+++ b/game.cpp
@@ -7784,6 +7784,8 @@ bool movepcto(int d, int subdir, bool checkonly) {
   
   if(multi::players == 1) monstersTurn();
 
+  save_memory();
+  
   check_total_victory();
 
   if(items[itWhirlpool] && cwt.c->land != laWhirlpool && !whirlpool::escaped) {
diff --git a/help.cpp b/help.cpp
index fa061c50..566bff1e 100644
--- a/help.cpp
+++ b/help.cpp
@@ -715,6 +715,7 @@ void describeMouseover() {
       }
       
     if(c->wall && !(c->wall == waChasm && c->land == laDual && ctof(c)) &&
+      !(c->land == laMemory) &&
       !((c->wall == waFloorA || c->wall == waFloorB) && c->item)) { 
       out += ", "; out += XLAT1(winf[c->wall].name); 
       
diff --git a/heptagon.cpp b/heptagon.cpp
index 586e1e79..b895e1d3 100644
--- a/heptagon.cpp
+++ b/heptagon.cpp
@@ -89,6 +89,7 @@ heptagon *buildHeptagon(heptagon *parent, int d, hstate s, int pard = 0, int fix
     h->c7 = NULL;
     h->emeraldval = 0;
     h->fiftyval = 0;
+    h->cdata = NULL;
     }
 //generateEmeraldval(parent);
 //generateEmeraldval(h);
diff --git a/hyper.h b/hyper.h
index 3be4f5e6..e60251ad 100644
--- a/hyper.h
+++ b/hyper.h
@@ -165,7 +165,7 @@ struct heptagon {
   int fieldval;
   // evolution data
   short rval0, rval1;
-  struct cdata *cdata;
+  struct cdata *cdata; // for alts, this contains the pointer to the original
   // central cell
   cell *c7;
   // associated generator of alternate structure, for Camelot and horocycles
@@ -2492,3 +2492,6 @@ void mainloop();
 void clearAnimations();
 
 transmatrix rotmatrix(double rotation, int c0, int c1);
+
+void destroycellcontents(cell *c);
+extern heptagon *last_cleared;
diff --git a/landgen.cpp b/landgen.cpp
index 35c802e5..ca1b96b9 100644
--- a/landgen.cpp
+++ b/landgen.cpp
@@ -2142,6 +2142,12 @@ void giantLandSwitch(cell *c, int d, cell *from) {
           c->monst = moRatling;
         }      
       break;
+    
+    case laMemory:
+      c->wall = waChasm;
+      if(d == 7 && !c->monst && hrand(2000) < 4)
+        c->monst = moGhost;
+      break;
     }
   }
 
diff --git a/landlock.cpp b/landlock.cpp
index 0e38c3bb..b29a9077 100644
--- a/landlock.cpp
+++ b/landlock.cpp
@@ -58,7 +58,8 @@ int isNative(eLand l, eMonster m) {
 
     case laCrossroads: case laCrossroads2: case laCrossroads3: case laCrossroads4: 
     case laCrossroads5:
-    case laNone: case laBarrier: case laOceanWall: case laCanvas: return 0;
+    case laNone: case laBarrier: case laOceanWall: case laCanvas: case laMemory: 
+      return 0;
     
     case laEmerald: 
       return (m == moFlailer || m == moLancer || m == moMiner) ? 2 : 
@@ -253,6 +254,7 @@ eItem treasureType(eLand l) {
     case laBarrier: return itNone;
     case laOceanWall: return itNone;
     case laCanvas: return itNone;
+    case laMemory: return itNone;
     
     case laEmerald: return itEmerald;
     case laWineyard: return itWine;
@@ -478,7 +480,7 @@ bool landUnlocked(eLand l) {
     case laEAir: case laEEarth: case laEWater: case laEFire:  case laElementalWall:
       return elementalUnlocked();
     
-    case laBarrier: case laNone: case laOceanWall: case laCanvas: case laCA:
+    case laBarrier: case laNone: case laOceanWall: case laCanvas: case laCA: case laMemory:
       return false;
     
     case laMirrorOld: