diff --git a/1623/41/survey.htm b/1623/41/survey.htm
index d192845ab..6d81aae4a 100644
--- a/1623/41/survey.htm
+++ b/1623/41/survey.htm
@@ -6,6 +6,7 @@
 <link rel="stylesheet" type="text/css" href="/css/main2.css" />
 </head>
 <body>
+<h1>Stellerwegh&ouml;hlensystem</h1>
 <h2>Stellerwegh&ouml;hlensystem surveys</h2>
 
 <p>Various low-grade surveys were published during the course of the
@@ -44,10 +45,10 @@ provide independent checks. The only known problem with the published
 survey is the section of passage drawn 46&deg; out due to the "fridge
 north" calibration cock-up.</p>
 
-<p>After the high entrances of <a href="/1623/41/143.htm">143</a> and
+<p>After the high entrances of <a href="/1623/143/143.htm">143</a> and
   <a href="/1623/41/144.htm">144</a> were explored, and the latter was connected
 into Stellerweg, and considerably more exploration was done in
-<a href="/1623/41/142.htm">142</a>, including two connections into the main
+<a href="/1623/142/142.htm">142</a>, including two connections into the main
 system, a lot more survey data was available, all of it above the Big Rift in
 Stellerweg. All these passages were drawn up, at a larger scale than the
 original published survey, and with the fridge north error corrected.
@@ -62,7 +63,7 @@ entrances. An overview of the whole survey (at a reduced scale) is also on
 the site <a href="hlevel.png">here</a>.
 A lot more survey work is expected in the cave over the next few
 years (and this has already started). One connection from
-  <a href="/1623/78/78.htm">Schwabenschacht</a> (1623/78) to the 1623/142 entrance
+  <a href="/1623/78/78.html">Schwabenschacht</a> (1623/78) to the 1623/142 entrance
 has already been made, and other connections seem likely. It is hoped that we
 will also be able to obtain details of the other caves connected to the
 system, and be able to draw up a full survey of what is already at least a