In the UK, the Environment Agency has used lidar, a modern laser-based surveying technique, to generate 3D maps. Altogether, the data collected covers about 72% of the land surface, and it amounts to about 11 TB. That is a huge amount of data.

While the Environment Agency used it to track coastlines and do planning of things like flood defenses, they've put it online last summer, so you can find it on their survey Open Data site now.

Of course, this is a wonderful tool for archaeologists as well, as the lidar scans can reveal buried structures. Among the archaeologists who have already used the scan data successfully is David Ratledge, who finally found the "missing" Roman road that connected Ribchester and Lancaster.

I always love it when new technology does wonderful stuff for archaeological research!