A lot of the surface evidence for archaeology in Britain is on cultivated land or in upland areas. Aerial photography has long been used to pick it out, and archaeologists choose their moment carefully. Field marks often show up best in low sunlight, especially in winter when vegetation is less overwhelming, or in droughts, or when there's been a light dusting of snow. Google Earth, for all its glories, doesn't focus in that way, though it does reveal much of interest. It's easy to find my house, which is very isolated and hard to get to, but unfortunately Google Earth's resolution is low in my area. I noticed that it's updated the images since I filled in my pond this time last year. I wonder how long it'll be before it picks up the fact that I've just spread five tons of different-coloured gravel on my drive. My back's killing me.