I am a little puzzled by this one. I have and area sand that when I compile the file (FrozenDeep) by itself works and shows up, but when compiled within the cave (reservoir) does not show up, however as far as I can tell all the other sand areas are working fine? I would be most grateful if someone could help solve this problem for me. I am using a custom (from the thrion wiki) sand but I have changed the area to water to and the same thing plus not used the custom sand by not using my common_layout file. The data for the Frozendeep is at http://www.cave-registry.org.uk/svn/CheddarCatchment/Reservoir/FrozenDeep/ compiled using the thconfig file in there the whole cave is at http://www.cave-registry.org.uk/svn/CheddarCatchment/Reservoir/ Again, compiled using the thconfig file in there thanks Andrew