Caves present a challenging environment to survey and map. Conditions are often wet, muddy and involve confined spaces. This talk will look at how the technology we have developed has changed how we measure and create maps of cave systems. From traditional sighting compasses, tape measures and paper and pencil, to laser measures, bluetooth data transfer and PDAs or mobile phones as recording and drawing devices. Then once the data is collected underground, how open source software has been developed by cavers to process the data and draw maps which adjust to later changes in positions of parts of the cave when more data is collected or corrected. We'll look at loop closures, explorations of places no person has gone before, and different ways to present a 3 dimensional map of a 70km cave system. There will be plenty of photographs and video clips of cave exploration, along with live software demos and viewing of digital maps.