The operators of a quarry at the summit of Moll's Gap have been told at the Circuit Court in Tralee to scale back production to 1964 levels, thereby halving production.
They must also construct a weighbridge to monitor exactly how much material is extracted each year. And they can increase operations by applying under the planning acts.
Kerry County Council had sought an order to halt work at the quarry, owned by Mr John Kissane and Mr Michael Kissane.
It also wants the owners to remove their machinery and restore the lands at the beauty spot in the Ring of Kerry. At an earlier hearing, Ms Liz Murphy for the council said the development interfered with the area's scenic character.
The council has noted large scale intensification of work at the quarry in recent years. It had monitored several 18-tonne trucks leaving the quarry daily and had established that 4,500 tonnes each month was now being extracted, as much as in a whole year in the 1960s.
Three enforcement notices had been issued since 2002, said the council's senior planning enforcement officer, Mr Keith Parrott.
But Mr Jackie Healy-Rae TD, in court for the all-day hearing, had worked in the quarry in the 1950s and 1960s and would say the quarry was equally busy in the 1960s, during which the council itself worked the quarry under lease from Mr John Kissane, Mr James Macken, for the quarry owners, told the court.
"He recalls 10-15 men working there," Mr Macken put it to Mr Joseph Purcell, assistant staff officer with Kerry County Council in the 1960s.
"We would have because stone had to be broken with sledges. Mr Healy-Rae's tractor and trailer and loading truck were used," Mr Purcell said. Just two men were now working in the quarry and using hydraulic equipment, the court heard.
Judge John O'Hagan saidit was clear that intensification had taken place and that usage had increased since 1963 (after which planning controls were introduced for quarries. He said it was not possible to stop the quarrying entirely but it could return to 1964 levels. Extraction should be cut back to 20,000 tonnes annually and he ordered a weighbridge to be installed within nine months.
The quarry owners had also agreed to apply for a licence and register it under Section 261 of the Planning Act by the end of March, by consent.