We've been trying to identify the location of the attached photo (
the full size photo is posted here), and after considering places as diverse as Ceylon, Egypt, and the Balkans in addition to the more obvious UK it now seems most likely to be somewhere in Glamorganshire or Pembrokeshire (the cap badge, uniform and equipment makes it most likely that the men are from the Glamorgan Yeomanry or Pembroke Yeomanry, and the landscape definitely has that British countryside look to it).
tonepad suggested that the building on the horizon near the horseman's rifle muzzle looked like the medieval dovecote at Llantwit Major in Glamorganshire, which it certainly does. While following that up I was googling for WWI army camps in Wales - I didn't find any near Llantwit Major but came across several photos of a pre/early WWI Yeomanry camp at Penally with a similar feature on the horizon -
see this and subsequent replies on the other topic for details and links.
So is this photo taken at Yeomanry Field in Penally ?
P.S. The Penally History Group posted several of the photos I found (and the alternative names in the title are from one of those). But although their website says to email them it doesn't give any email address ! With luck one of them is a member here.