People living at Blaenau Ffestiniog in Gwynedd want a slate wall in front of their homes reduced in size.
The wall is 6ft talll in places and blocks residents' views
The wall - which ranges from 4-6ft (1-1.8m) in height - was built as part of a road-widening on the A470 between Blaenau and Dolwyddelan.
Residents in Oakeley Terrace welcomed the road scheme but claim the wall is too high and is blocking their view of open countryside.
A Welsh Assembly Government spokesman said the matter was being investigated.
Rowena Jones said the residents were told it would be a 'dwarf' wall which would not affect their view.
But she said all she could see from her living room was a wall of slate.
"I really miss the view, I could see open countryside and now all I see is the wall."
The structure itself was "very nice, just too high", she said.
Despite its height it did not cut down on traffic noise either.
"No-one here likes the wall and I hope it is not too late to change the height," she added.
Another resident Edmund Humphreys said the structure was spoiling his enjoyment of his garden.
He said he used to enjoy sitting outside with a glass of wine, soaking in a view of fields and sheep, backed by the mountains.
Gwynedd councillor Ernest Williams said he sympathised with the residents.
"It has affected what they can see from their homes," he said.
"I feel the wall should be reduced in height by a couple of feet," he added.
A Welsh Assembly Government spokesman said the matter was being investigated by officials to see "what commitments have been made to the residents".