A High Court hearing has begun into plans to erect a 17km line of pylons, costing about £16m, along the Denbighshire and Conwy border.
SP Manweb was granted permission to run 10.5 miles of overhead cables between two wind farms in Clocaenog Forest to a substation near St Asaph, last year.
But local action group Pylon the Pressure won the right to a judicial review.
It claims the double wooden poles would be a blight on the countryside.
Part of the cables would pass near the 16th Century Berain Farm, Llannefydd, which was home to Catrin o Ferain, the granddaughter of Henry VII and a prominent member of the Tudor gentry in Wales.
At Monday's hearing in Llangefni, Peter Dickson, the barrister representing the pressure group, argued the cables should be placed underground near the farm.
He said the option was not considered by SP Manweb and Secretary of State Greg Clark should not have granted permission.
Government barrister Richard Moules argued the secretary of state had given it adequate consideration and placing the cables underground would cost twice as much as the £16m it will take to carry it along twin wooden poles.
Mr Moules said the authorities had decided against burying the cables at Berain Farm as it would "not be justified".
He also argued the fact permission for the overhead line was given for only 30 years was in part in recognition of the "heritage value" of Berain Farm.
Mark Westmoreland-Smith, acting on behalf of the power company, insisted they had considered "in depth" the potential of burying the cable, both at Berain Farm and along the length of the project.
Mr Justice Lewis has said he will reserve judgement on the case, which was adjourned until Tuesday.