For years, the United Kingdom's Environment Agency has been using Lidar to study flooding and coastal changes. Since 1998, it's had an unexpected use: discovering long-lost roads left by the Romans, helping to uncover new details of the country's past. The Romans were renowned for their infrastructure projects, and their efforts extended far into Great Britain.
For decades after the 43AD invasion, a large region of the North (including Lancashire, Yorkshire and Cumbria) was controlled by a Celtic tribe known as the Brigantes. Tacitus writes that it was the collapse of the marriage between Queen Cartimandua of the Brigantes, a Roman ally, and her husband Venetius that led to a showdown with Rome. Following their divorce, Venetius organised a revolt in 69AD and Cartimandua fled. The Emperor Vespasian then sent a force under Britain's new governor, Quintus Petilius Cerialis, to put down the rebellion and conquer northern England. Building roads to link up forts and settlements across this rugged landscape was a vital part of this decades-long conquest of the North.
Recently, archaeologists have been working to uncover Rome's work in England, and using Lidar, they have discovered several kilometres of roadway between Ribchester and Lancaster.
The UK's Environmental Agency has discovered other roads using the technology, discovering roads and structures in across England.
These efforts are important, because they tell us a couple of things about Roman Britain: the infrastructure shows where people were moving about and in what routes, but also what was deemed a priority for the Romans, which in turn sheds some light on what relations might have been like between Romans and Northern tribes.