Choosing Hadrian's Wall as one of my favourite places is a bit of a cheat, really, as it is a 73-mile long (80 Roman miles) wall punctuated with a whole range of 20 individual sites each worth a visit; from mile castles and forts to desolate sections with fabulous views or Roman settlements which are now busy market towns. There are various theories about why the wall was built: to keep the soldiers occupied on what was quite a boring posting; to keep out the Celts; or to control and monitor the movement of traders between the areas - probably collecting taxes from those who did so. In addition to the soldiers, lots of administration staff, craftsmen, doctors and medical orderlies, stable hands, priests, clerks and messengers would have been based here
