diff --git a/umap/decorators.py b/umap/decorators.py
index 5e808d12..a0bb757f 100644
--- a/umap/decorators.py
+++ b/umap/decorators.py
@@ -1,10 +1,11 @@
 from functools import wraps
 
 from django.conf import settings
+from django.core.exceptions import PermissionDenied
 from django.http import HttpResponseForbidden
 from django.shortcuts import get_object_or_404
 from django.urls import reverse_lazy
-
+from django.utils.translation import gettext as _
 from .models import Map, Team
 from .views import simple_json_response
 
@@ -55,7 +56,7 @@ def can_view_map(view_func):
         map_inst = get_object_or_404(Map, pk=kwargs["map_id"])
         kwargs["map_inst"] = map_inst  # Avoid rerequesting the map in the view
         if not map_inst.can_view(request):
-            return HttpResponseForbidden()
+            raise PermissionDenied(_("This map is not publicly available"))
         return view_func(request, *args, **kwargs)
 
     return wrapper
diff --git a/umap/static/umap/content.css b/umap/static/umap/content.css
index 392ac85a..a9b849bc 100644
--- a/umap/static/umap/content.css
+++ b/umap/static/umap/content.css
@@ -208,31 +208,34 @@ input[type="submit"],
 }
 
 /* **************************** */
-/*             404              */
+/*             40x              */
 /* **************************** */
-.content404 {
-    width: 400px;
+.content-40x {
+    width: 600px;
     margin-left: auto;
     margin-right: auto;
     margin-top: 100px;
-    text-align: center;
 }
-.content404 a {
+.content-40x a {
     color: #3A4259;
 }
-.content404 h1 {
-    font-size: 10em;
+.content-40x h1 {
+    font-size: 2em;
     margin-bottom: 0;
     line-height: 0.5em;
     margin-top: 40px;
 }
-.content404 h2 {
-    font-size: 4em;
-    margin-top: 0;
-}
-.content404 img {
+.content-404 img {
     width: 32%;
 }
+.page-40x {
+    background-image: url('./img/logo_lightcyan.svg');
+    background-repeat: no-repeat;
+    background-size: contain;
+    background-position: center;
+    width: 100vw;
+    height: 90vh;
+}
 
 
 /* **************************** */
diff --git a/umap/static/umap/img/logo_lightcyan.svg b/umap/static/umap/img/logo_lightcyan.svg
new file mode 100644
index 00000000..76afe72f
--- /dev/null
+++ b/umap/static/umap/img/logo_lightcyan.svg
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg viewBox="0 0 128 128" width="128" height="128" version="1.1" id="svg2" sodipodi:docname="logo_lightgreen.svg" inkscape:version="1.4 (e7c3feb100, 2024-10-09)" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg">
+  <defs id="defs2" />
+  <sodipodi:namedview id="namedview2" pagecolor="#ffffff" bordercolor="#666666" borderopacity="1.0" inkscape:showpageshadow="2" inkscape:pageopacity="0.0" inkscape:pagecheckerboard="0" inkscape:deskcolor="#d1d1d1" inkscape:zoom="6.25" inkscape:cx="63.92" inkscape:cy="64" inkscape:window-width="1920" inkscape:window-height="1011" inkscape:window-x="0" inkscape:window-y="0" inkscape:window-maximized="1" inkscape:current-layer="svg2" />
+  <path d="M36.5 6.2A64 64 0 0 0 64 128C14.5 81.8 3.1 24.8 36.5 6.2zM64 128A64 64 0 0 0 91.5 6.2c33.4 18.6 22 75.6-27.5 121.8z" fill="#263B58" id="path1" style="fill:#eafcf1;fill-opacity:1" />
+  <path d="M87.7 33.8a23.7 23.7 0 1 1-47.4 0 23.7 23.7 0 0 1 47.4 0z" fill="#263B58" id="path2" style="fill:#eafcf1;fill-opacity:1" />
+</svg>
diff --git a/umap/templates/403.html b/umap/templates/403.html
new file mode 100644
index 00000000..3423b869
--- /dev/null
+++ b/umap/templates/403.html
@@ -0,0 +1,11 @@
+{% extends "40x.html" %}
+
+{% load i18n %}
+
+{% block content %}
+  <div class="content-40x">
+      <h1>{{ exception }}</h1>
+      <p>{% blocktrans %}<a href="">Find out here</a> how to manage map permissions.{% endblocktrans %}</p>
+      <p><a href="{% url 'home' %}">{% trans "Go back home" %}</a></p>
+  </div>
+{% endblock %}
diff --git a/umap/templates/404.html b/umap/templates/404.html
index aba82456..4d9cd80f 100644
--- a/umap/templates/404.html
+++ b/umap/templates/404.html
@@ -1,19 +1,10 @@
-{% extends "base.html" %}
+{% extends "40x.html" %}
 
 {% load i18n static %}
 
 {% block content %}
-  <div class="content404">
-    <a href="{% url "home" %}"
-       title="{% trans "Take me to the home page" %}">
-      <h1>
-        4
-        <img alt="0" width="128px" height="128px" src="{% static "umap/img/logo.svg" %}">
-        4
-      </h1>
-      <h2>
-        Not Found
-      </h2>
-    </a>
+  <div class="content-40x content-404">
+    <h1>404 Not Found</h2>
+    <p><a href="{% url 'home' %}">{% trans "Go back home" %}</a></p>
   </div>
 {% endblock content %}
diff --git a/umap/templates/40x.html b/umap/templates/40x.html
new file mode 100644
index 00000000..1fda935e
--- /dev/null
+++ b/umap/templates/40x.html
@@ -0,0 +1,9 @@
+{% extends "base.html" %}
+
+{% load umap_tags %}
+{% block body_class %}page-40x{% endblock body_class %}
+{% block extra_head %}
+  {% umap_css %}
+  {{ block.super }}
+  {% umap_js %}
+{% endblock extra_head %}