I visited Hadrian's Wall in October 2015 whilst in the area for a family reunion. We walked a circular route of about 10km, starting in the Northumbrian hamlet of 'Once Brewed', walking along the wall and taking in two of the ruined Roman forts - Housesteads and Vindolanda (although without paying to enter them).

There is quite a view of the lakes below from the ridgeline between Once Brewed and Housesteads, so I can recommend it as a section worth visiting. Having said that, there was little to see but fog when we went.

Hopefully somebody can visit and review the Antonine Wall for us, since nobody seems to have covered this recent addition yet.