diff --git a/core/views/caves.py b/core/views/caves.py
index 9d2512d..5ac3725 100644
--- a/core/views/caves.py
+++ b/core/views/caves.py
@@ -203,8 +203,10 @@ def file3d(request, cave, cave_id):
     - If the expected .3d file corresponding to cave.survex_file is present, return it.
     - If the cave.survex_file exists, generate the 3d file, cache it and return it
     - Use the cave_id to guess what the 3d file might be and, if in the cache, return it
-    - Use the cave_id to guess what the .svx file might be and generate the .3d file and return it
-    - (Use the incomplete cave.survex_file and a guess at the missing directories to guess the real .svx file location ?)
+    
+    There is a problem as the filename is shown of all areacode information, so both 1624-161 and 1623-161 
+    have a file called 161.svx and return a file called "161.3d" which may 
+    get incorrectly cached by other software (i.e your browser)
     """
 
     def runcavern(survexpath):
@@ -212,9 +214,7 @@ def file3d(request, cave, cave_id):
         as done in runcavern3d() in parsers/survex.py
         Needs testing.
         """
-        # print(" -  Regenerating cavern .log and .3d for '{}'".format(survexpath))
         if not survexpath.is_file():
-            # print(" -  - Regeneration ABORT\n -  - from '{}'".format(survexpath))
             pass
         try:
             completed_process = subprocess.run(
@@ -232,37 +232,33 @@ def file3d(request, cave, cave_id):
             print(" -  - Regeneration stdout: ", completed_process.stdout)
             print(" -  - Regeneration cavern log output: ", op3dlog.read_text())
 
-    def return3d(threedpath):
+    def return3d(threedpath, cave):
+        newfilename = cave.slug() + ".3d" # add the "1623-" part of the filename effectively.
         if threedpath.is_file():
             response = HttpResponse(content=open(threedpath, "rb"), content_type="application/3d")
-            response["Content-Disposition"] = f"attachment; filename={threedpath.name}"
+            response["Content-Disposition"] = f"attachment; filename={newfilename}"
             return response
         else:
             message = f'<h1>Path provided  does not correspond to any actual 3d file.</h1><p>path: "{threedpath}"'
-            # print(message)
             return HttpResponseNotFound(message)
 
-    survexname = Path(cave.survex_file).name  # removes directories
+    survexname = Path(cave.survex_file).name  # removes directories ie 1623/161/161.svx -> 161.svx 
     survexpath = Path(settings.SURVEX_DATA, cave.survex_file)
-    threedname = Path(survexname).with_suffix(".3d")  # removes .svx, replaces with .3d
-    threedpath = Path(settings.SURVEX_DATA, threedname)
-
+    survexdir  = survexpath.parent
+    threedname = Path(survexname).with_suffix(".3d")  # removes .svx, replaces with .3d AND DISCARDS PATH arrgh
+    threedpath = survexpath.parent / threedname
+ 
     # These if statements need refactoring more cleanly
     if cave.survex_file:
-        # print(" -  cave.survex_file '{}'".format(cave.survex_file))
         if threedpath.is_file():
-            # print(" -  threedpath '{}'".format(threedpath))
-            # possible error here as several .svx files of same names in different directories will overwrite in /3d/
             if survexpath.is_file():
                 if os.path.getmtime(survexpath) > os.path.getmtime(threedpath):
                     runcavern(survexpath)
-            return return3d(threedpath)
+            return return3d(threedpath, cave)
         else:
-            # print(" -  - survexpath '{}'".format(survexpath))
             if survexpath.is_file():
-                # print(" -  -  - survexpath '{}'".format(survexpath))
                 runcavern(survexpath)
-                return return3d(threedpath)
+                return return3d(threedpath, cave)
 
     # Get here if cave.survex_file was set but did not correspond to a valid svx file
     if survexpath.is_file():
@@ -279,7 +275,6 @@ def rendercave(request, cave, slug, cave_id=""):
     """Gets the data and files ready and then triggers Django to render the template.
     The resulting html contains urls which are dispatched independently, e.g. the 'download' link
     """
-    # print(" ! rendercave:'{}' START slug:'{}' cave_id:'{}'".format(cave, slug, cave_id))
 
     if cave.non_public and settings.PUBLIC_SITE and not request.user.is_authenticated:
         return render(request, "nonpublic.html", {"instance": cave, "cavepage": True, "cave_id": cave_id})
diff --git a/templates/cave.html b/templates/cave.html
index 3e94747..a04bb93 100644
--- a/templates/cave.html
+++ b/templates/cave.html
@@ -5,7 +5,7 @@
 <!--
 # We put every .3d file in the same folder as 
 # the .svx file, using the {{svx3d}} template variable set in rendercave() in 
-# core/views/caves.py but with a full path. THIS IS NOW DONE March 2022.
+# core/views/caves.py .
 #-->
 <link type="text/css" href="/javascript/CaveView/css/caveview.css" rel="stylesheet"/>
 <script type="text/javascript" src="/javascript/CaveView/js/CaveView2.js" ></script>
@@ -18,7 +18,7 @@
         const viewer = new CV2.CaveViewer( 'scene', {
             home: '/javascript/CaveView/',
             //Wookey old code surveyDirectory: '/expowebcache/3d/',
-            surveyDirectory: '/cave/3d/',
+            surveyDirectory: '/cave/3d/', // this is a fake Django url which should return the right place
             terrainDirectory: '/loser/surface/terrain/'  // cannot work, apache not handling this url
         } );
 
@@ -27,7 +27,8 @@
         const ui = new CV2.CaveViewUI( viewer );
 
         //Wookey old code: ui.loadCave('{{svx3d}}.3d');
-        ui.loadCave('{{ cave }}.3d');
+	    //Wookey new code
+ 	    ui.loadCave('{{ cave }}.3d'); // ie '1624-161.3d' Troggle used to return a file 161.3d but now returns 1623-161.3d
 
         document.getElementById('scene').style.cssText = "background-color: rgb(0, 0, 0); position: relative !important;"
     }
@@ -42,7 +43,7 @@
 {% block contentheader %}
 <table id="cavepage">
 <tr>
-    <th id="kat_no"><!-- why is this not showing unofficial_number??-->
+    <th id="kat_no">
         {{  cave.areacode}} /
         {% if cave.kataster_number %}
             {{ cave.kataster_number|safe }}
@@ -205,7 +206,7 @@
 {% if cave.survex_file %}
     Primary <a href="/survexfile/{{cave.survex_file}}">survex file</a> for this cave 
  <br>
-    Download .3d file <a href="{% url "cave3d" cave %}">{% url "cave3d" cave %}</a>
+    Download .3d file <a href="{% url "cave3d" cave %}">{{cave}}.3d</a><!-- this is a fake directory -->
 <br>
 cave survex path '{{ cave.areacode }}/{% if cave.kataster_number %}{{cave.kataster_number}}{% else %}{{cave.unofficial_number}}{% endif %}/'
     <div id='scene'></div>