Now Il let you in to a secret... I am actually quite a barn fan. Not normal farm barns, but remote hill ones. And this is why.... if you know where to look, they can actually give a great insight in to the lifes of the people who lived there, in the form of graffiti on the old corn threshing machines, which still exist in about 70% of all remote hill farm barns and byres....
for example (links to my flickr)
this big wooden thing is a good example of the old corn threshing machines
http://www.flickr.com/photos/scotlands-forgotten-places/2345610513/in/set-72157604164501446/
here's a date (1843) - so it gives you an idea of what sort of times you can see
http://www.flickr.com/photos/scotlands-forgotten-places/2346439888/in/set-72157604164501446/
http://www.flickr.com/photos/scotlands-forgotten-places/2346440876/in/set-72157604164501446/
there are so many out there, and it's not just dates. I've seen sheep counts, community news (remember these now empty remote glens were once full of old farms and crofts as late as the 1960's), an appeal for a missing woman from a farm last seen "wearing wullie Gordon's clothes", little bits about winter weather and harsh frosts in the 1800's, pictures of people, and even a cocky young farm hand writing " [womans name] is a great worker between the bed sheets"
And then they wonder why they had families of 12!!