An inquiry is being held into whether or not a wind farm can be built at a beauty spot in Swansea.
The proposed Mynydd y Gwair development is on common land so the inquiry will decide whether that land can be exchanged and used to generate energy.
There have already been two previous inquiries into the proposals for 16 turbines.
Swansea council granted planning permission to RWE Innogy UK for the wind farm in 2013.
But the company needed to deregister the common land near Felindre and provide alternative space.
That was refused last year by deputy minister Rebecca Evans after considering a planning inspector’s report.