Leaving aside HA (which quite properly IMHO has a rather conservative approach) I'd like to suggest that there are some exceptional cases such as Avebury where a conservative approach is wrong (though it's likely to persist, I'm afraid).

So far as I know, the ONLY reasons why re-erection doesn't and probably won't take place is a fear of losing evidence/a fear of not knowing enough to do it right/ a general perception that the issue should be bequeathed to some future generation who might be better placed to do it better. Keiller fell down, big time, on all these things, and yet on balance I'm very glad he did what he did. Who isn't? In the end, he has given enormous pleasure to enormous numbers of people. Some knowledge has been lost. So be it. Why shouldn't there be cases where that is seen as more important than the needs of academics or the deification of some cold god called Archaeology? This isn't a plea for yob culture or Disneyfication, merely a suggestion that the dividing line is drawn too tightly in some cases.

A secondary point: I get the impression that archaeology has become SO revered and sacrosanct that relatively "recent" happenings are considered equally important parts of it. Two examples: the rediscovery, exposure and re-burial of the Beckhampton Avenue stones, which I found pretty ridiculous, was accompanied by some talk of the need to learn about and preserve the evidence of the stone-burning techniques. Hmmm. Personally, I'd rather lose that knowledge and have them up. Second, the EH approach to Silbury is absolutely dripping with anxiety to study the 18th and 19th century excavated tunnels. Insofar as it leads the repair process away from the no-nonsense mining engineers approach to stabilisation, that's an example where the great god archaeology is not only getting above his station but is actually damaging our heritage.

So, as I say, get 'em up, let's have some fun.