How ‘old’ does a structure or hedge need to be, to leave a visible trace or ‘ghost’ line visible today? William Makeham

A structure doesn’t need to be very old at all before it leaves a visible trace on the landscape. That’s why archaeologists need to be very careful when deciding what these traces represent. A line seen from the air crossing a field could be a prehistoric boundary ditch or a modern pipe trench and even things like the spot where a modern circular cattle feeder has stood can for a while leave a mark that looks very like a ploughed down Bronze Age round barrow. Getting that view from above is very important for helping to understand landscapes but it’s also important to know what has been going on in recent years – from maps and from talking to local farmers. So beware jumping to conclusions!