Michael:

> why are manmade works considered unnatural in highpointing

Much debate over this in Scotland. A notorious case involved a
forty-foot cairn erected on top of Ben Lawers by some Victorian
landowner, solely in order to promote it to our (very small) group of
4000-footers. In another case, there's a hill-list called the Marilyns
which involves a minimum qualifying reascent (the height you have to
climb to get to the top from the highest connecting ridge or col); one
hill qualifies only because of a railway-cutting which divides the
connecting ridge. So there's a debate about *intent*, and there's also
a debate, as you say, about artificiality in what is a very natural
endeavour. No-one, for instance, would insist that you shin up a radio
mast in order to have properly climbed a hill - so then the radio mast
can't really be part of the hill.
But hundreds of Scottish hills are crowned with Iron Age forts, in the
same way that hundreds of Danish hills have barrows. And one of the
problems I see there is that no-one knows what height the hill was
before the fort/barrow was built. It seems possible to me that 173m
Yding Skovhoj was 173m high before the barrow-boys got to it - some
degree of site-levelling might have occurred.
And the fact that there is such a thing as the Ejer Baunehoj Society
makes me wonder if this isn't a minority view. We don't have a Ben
Nevis Society or a Denali Society championing their supremacy, for
instance. (Can you shed any light, Jesper?) Certainly most sources
I've seen give Yding Skovhoj as the Danish highest point. (But then,
most sources outside South Africa give Injasuti as the South African
highest point, and that's wrong!)

And Jesper:

> There are probably buildings in DK higher than these hills.

An extreme example of this sort of thing is the Marshallese story that
the highest point in their country is a canal bridge in Majuro, 20ft
high. Presumably they have no two-storey buildings ...

Grant