What's truly a shame is that large sections of Hadrian's Wall remained mostly intact for 1600 years, only to almost entirely disappear in the 1700s when an English general running from sea to sea along the Scottish border slaughtering all the Scottish soldiers he could find, decided he needed a paved road to speed up his troop movements, and dismantled most of what was left of the Wall to use the stones for that purpose.
Most of the use of the Wall as a quarry was on a small scale, the local gentry using the dressed stone for various structures, including homes. A British General used stones from the Wall to improve a road (which is still in use) for troop movements during the Jacobite rebellion (it sez here). Nevertheless, quite a lot of the Wall has survived, and other parts were restored during the Victorian Era and before.
About ten years ago, well, probably more like 15 now, I read an amusing anecdote from a recent tourist to England. She posted a photo she'd taken of a pile of stones, conveniently located near a pub. The tour bus driver had stopped the vehicle, stated that the pile of stones was all that was left of the famous Hadrian's Wall, then shut off the engine, inviting everyone to join him on their own nickel to enjoy a pint at the pub. She believed his story about the pile of stones.
BTW, just to head the coming subthread off at the pass...