(I just sent this to the forum from a different email account and it seems not to have got through - apologies if you get it twice) I made some progress with the 3D cave visualisation in Google Earth. If I manually change the start of each linestring in the model kml file like this; <LineString> <altitudeMode>absolute</altitudeMode> <coordinates> 172.88465190008699, -40.99745081569796, 701.33433538689223 ... Ie add the altitudemode Then with the terrain layer turned off one can see the cave in 3d at it's true altitude over a flat aerial photograph. Not ideal, but a useful alternative to seeing the surface projection on the surface. Now if only the ground surface could be made translucent... Maybe therion should have an option to select the AltitudeMode to use for model generation. Also it would be nice to have the map -title in one of the kml fields below in place of the current text <name>Therion KML export</name> <description>Therion KML export.</description> Bruce