The map title displays the eventual filtering tag in its title

app/views/maps/index.html.haml

@@ -1,6 +1,10 @@
 %h2
   %em.fa.fa-map-marker
-  =title t '.title'
+  = title t '.title'
+  - if params[:tag]
+    «
+    %em= params[:tag]
+    »
 
 #map.events(data-url="#{maps_path format: :json}")
 

app/views/tags/show.html.haml

@@ -1,5 +1,5 @@
 %h2
-  =t '.title'
+  = t '.title'
   «
   %em= params[:id]
   »