12:19 Nov 25, 2011 

I now understand Wendy has the original sentence in her answer, so the verb should definitely be singular. My apologies for the misunderstanding Wendy, I thought that was jsut an example of it in use..

12:08 Nov 25, 2011 

Nicola! The same old context pulling contest. Taffy tastes better.
Hope all's well with you!

12:06 Nov 25, 2011 

I think Wendy is also correct to identify this as Austrian German, it seems a fairly commonly used construction here. However, whether the verb should be singular or plural depends on what, if anything, is missing after the "und". Some feedback form the asker would be nice!

12:03 Nov 25, 2011 

I would tend to agree with Hermann and say the "und" shouldn't be there, at least not in the quoted (and possibly shortened) version. But then the verb also needs to be changed to singular (as pointed out by Wendy Streitparth in her answer): Ein traumhafter Ausblick [...] tut das Seine dazu (or "das Seinige").

I guess the originial source text does name the "Hausberge" which then in turn confused the author and led to the singular/plural error (tun das Ihre vs. tut das Seine).

11:15 Nov 25, 2011 

...

08:58 Nov 25, 2011 

There's something missing after "und".

08:47 Nov 25, 2011 

The German phrase should be "tun das Ihrige dazu" as in to render one's contribution.

Here I'd go with something general like "To top it off there is the fabulous mountain panorama..."

08:44 Nov 25, 2011 

... and the grammar is incorrect. But as far as I can guess from the context, it means something like: the view of the mountains "add to this in their very own way". But, like I said, there is something important missing directly before "tun das Ihre hierzu".

08:43 Nov 25, 2011 

I would have understood it as something along the lines of play their part/ make their contribution/ add to this, but it would need another noun after the und

i.e. A fabulous view over the mountains with the local landmark mountains and.... make their contribution to this (the overall effect - guessing that this is what the hierzu refers to)/ contribute to the overall effect