Castleguard Cave is well known to cavers around the world. In addition to being Canada's longest cave, it is the only cave in the world with passages plugged by ice pushed in from a surface icefield. Because the entrance floods unpredictably, Castleguard Cave can only be safely visited in winter, which enhances its remote, beautiful setting.
The mapping of Castleguard Cave began with its exploration in the 1960s, and over the next thirty years its survey data grew to include over twenty kilometres of passages. But because the cave is very linear, the sheer scale of producing a detailed map on paper defied the best efforts of cavers for decades - a usable scale of 1:1000 would have required a piece of paper six metres long.
The answer, of course, was computer technology. The Castleguard Cave Survey is now available as a navigable PDF file available as a free download from here, on the Caving Canada site. Alternatively, you can obtain a CD from the Alberta Speleological Society treasurer for $8 ($10 if outside of Canada).